/*
 *  Copyright (c) 2011 The WebRTC project authors. All Rights Reserved.
 *
 *  Use of this source code is governed by a BSD-style license
 *  that can be found in the LICENSE file in the root of the source
 *  tree. An additional intellectual property rights grant can be found
 *  in the file PATENTS.  All contributing project authors may
 *  be found in the AUTHORS file in the root of the source tree.
 */

#include "webrtc_ns.h"

#include <assert.h>
#include <math.h>
#include <string.h>
#include <stdlib.h>
#include <stdio.h>

#include "cpu_features_wrapper.h"
#include "nsx_core.h"

// Skip first frequency bins during estimation. (0 <= value < 64)
static const int kStartBand = 5;

// Constants to compensate for shifting signal log(2^shifts).
const WebRtc_Word16 WebRtcNsx_kLogTable[9] = {
  0, 177, 355, 532, 710, 887, 1065, 1242, 1420
};

const WebRtc_Word16 WebRtcNsx_kCounterDiv[201] = {
  32767, 16384, 10923, 8192, 6554, 5461, 4681,
  4096, 3641, 3277, 2979, 2731, 2521, 2341, 2185, 2048, 1928, 1820, 1725, 1638, 1560,
  1489, 1425, 1365, 1311, 1260, 1214, 1170, 1130, 1092, 1057, 1024, 993, 964, 936, 910,
  886, 862, 840, 819, 799, 780, 762, 745, 728, 712, 697, 683, 669, 655, 643, 630, 618,
  607, 596, 585, 575, 565, 555, 546, 537, 529, 520, 512, 504, 496, 489, 482, 475, 468,
  462, 455, 449, 443, 437, 431, 426, 420, 415, 410, 405, 400, 395, 390, 386, 381, 377,
  372, 368, 364, 360, 356, 352, 349, 345, 341, 338, 334, 331, 328, 324, 321, 318, 315,
  312, 309, 306, 303, 301, 298, 295, 293, 290, 287, 285, 282, 280, 278, 275, 273, 271,
  269, 266, 264, 262, 260, 258, 256, 254, 252, 250, 248, 246, 245, 243, 241, 239, 237,
  236, 234, 232, 231, 229, 228, 226, 224, 223, 221, 220, 218, 217, 216, 214, 213, 211,
  210, 209, 207, 206, 205, 204, 202, 201, 200, 199, 197, 196, 195, 194, 193, 192, 191,
  189, 188, 187, 186, 185, 184, 183, 182, 181, 180, 179, 178, 177, 176, 175, 174, 173,
  172, 172, 171, 170, 169, 168, 167, 166, 165, 165, 164, 163
};

const WebRtc_Word16 WebRtcNsx_kLogTableFrac[256] = {
  0,   1,   3,   4,   6,   7,   9,  10,  11,  13,  14,  16,  17,  18,  20,  21,
  22,  24,  25,  26,  28,  29,  30,  32,  33,  34,  36,  37,  38,  40,  41,  42,
  44,  45,  46,  47,  49,  50,  51,  52,  54,  55,  56,  57,  59,  60,  61,  62,
  63,  65,  66,  67,  68,  69,  71,  72,  73,  74,  75,  77,  78,  79,  80,  81,
  82,  84,  85,  86,  87,  88,  89,  90,  92,  93,  94,  95,  96,  97,  98,  99,
  100, 102, 103, 104, 105, 106, 107, 108, 109, 110, 111, 112, 113, 114, 116, 117,
  118, 119, 120, 121, 122, 123, 124, 125, 126, 127, 128, 129, 130, 131, 132, 133,
  134, 135, 136, 137, 138, 139, 140, 141, 142, 143, 144, 145, 146, 147, 148, 149,
  150, 151, 152, 153, 154, 155, 155, 156, 157, 158, 159, 160, 161, 162, 163, 164,
  165, 166, 167, 168, 169, 169, 170, 171, 172, 173, 174, 175, 176, 177, 178, 178,
  179, 180, 181, 182, 183, 184, 185, 185, 186, 187, 188, 189, 190, 191, 192, 192,
  193, 194, 195, 196, 197, 198, 198, 199, 200, 201, 202, 203, 203, 204, 205, 206,
  207, 208, 208, 209, 210, 211, 212, 212, 213, 214, 215, 216, 216, 217, 218, 219,
  220, 220, 221, 222, 223, 224, 224, 225, 226, 227, 228, 228, 229, 230, 231, 231,
  232, 233, 234, 234, 235, 236, 237, 238, 238, 239, 240, 241, 241, 242, 243, 244,
  244, 245, 246, 247, 247, 248, 249, 249, 250, 251, 252, 252, 253, 254, 255, 255
};

static const WebRtc_Word16 kPowTableFrac[1024] = {
  0,    1,    1,    2,    3,    3,    4,    5,
  6,    6,    7,    8,    8,    9,   10,   10,
  11,   12,   13,   13,   14,   15,   15,   16,
  17,   17,   18,   19,   20,   20,   21,   22,
  22,   23,   24,   25,   25,   26,   27,   27,
  28,   29,   30,   30,   31,   32,   32,   33,
  34,   35,   35,   36,   37,   37,   38,   39,
  40,   40,   41,   42,   42,   43,   44,   45,
  45,   46,   47,   48,   48,   49,   50,   50,
  51,   52,   53,   53,   54,   55,   56,   56,
  57,   58,   58,   59,   60,   61,   61,   62,
  63,   64,   64,   65,   66,   67,   67,   68,
  69,   69,   70,   71,   72,   72,   73,   74,
  75,   75,   76,   77,   78,   78,   79,   80,
  81,   81,   82,   83,   84,   84,   85,   86,
  87,   87,   88,   89,   90,   90,   91,   92,
  93,   93,   94,   95,   96,   96,   97,   98,
  99,  100,  100,  101,  102,  103,  103,  104,
  105,  106,  106,  107,  108,  109,  109,  110,
  111,  112,  113,  113,  114,  115,  116,  116,
  117,  118,  119,  119,  120,  121,  122,  123,
  123,  124,  125,  126,  126,  127,  128,  129,
  130,  130,  131,  132,  133,  133,  134,  135,
  136,  137,  137,  138,  139,  140,  141,  141,
  142,  143,  144,  144,  145,  146,  147,  148,
  148,  149,  150,  151,  152,  152,  153,  154,
  155,  156,  156,  157,  158,  159,  160,  160,
  161,  162,  163,  164,  164,  165,  166,  167,
  168,  168,  169,  170,  171,  172,  173,  173,
  174,  175,  176,  177,  177,  178,  179,  180,
  181,  181,  182,  183,  184,  185,  186,  186,
  187,  188,  189,  190,  190,  191,  192,  193,
  194,  195,  195,  196,  197,  198,  199,  200,
  200,  201,  202,  203,  204,  205,  205,  206,
  207,  208,  209,  210,  210,  211,  212,  213,
  214,  215,  215,  216,  217,  218,  219,  220,
  220,  221,  222,  223,  224,  225,  225,  226,
  227,  228,  229,  230,  231,  231,  232,  233,
  234,  235,  236,  237,  237,  238,  239,  240,
  241,  242,  243,  243,  244,  245,  246,  247,
  248,  249,  249,  250,  251,  252,  253,  254,
  255,  255,  256,  257,  258,  259,  260,  261,
  262,  262,  263,  264,  265,  266,  267,  268,
  268,  269,  270,  271,  272,  273,  274,  275,
  276,  276,  277,  278,  279,  280,  281,  282,
  283,  283,  284,  285,  286,  287,  288,  289,
  290,  291,  291,  292,  293,  294,  295,  296,
  297,  298,  299,  299,  300,  301,  302,  303,
  304,  305,  306,  307,  308,  308,  309,  310,
  311,  312,  313,  314,  315,  316,  317,  318,
  318,  319,  320,  321,  322,  323,  324,  325,
  326,  327,  328,  328,  329,  330,  331,  332,
  333,  334,  335,  336,  337,  338,  339,  339,
  340,  341,  342,  343,  344,  345,  346,  347,
  348,  349,  350,  351,  352,  352,  353,  354,
  355,  356,  357,  358,  359,  360,  361,  362,
  363,  364,  365,  366,  367,  367,  368,  369,
  370,  371,  372,  373,  374,  375,  376,  377,
  378,  379,  380,  381,  382,  383,  384,  385,
  385,  386,  387,  388,  389,  390,  391,  392,
  393,  394,  395,  396,  397,  398,  399,  400,
  401,  402,  403,  404,  405,  406,  407,  408,
  409,  410,  410,  411,  412,  413,  414,  415,
  416,  417,  418,  419,  420,  421,  422,  423,
  424,  425,  426,  427,  428,  429,  430,  431,
  432,  433,  434,  435,  436,  437,  438,  439,
  440,  441,  442,  443,  444,  445,  446,  447,
  448,  449,  450,  451,  452,  453,  454,  455,
  456,  457,  458,  459,  460,  461,  462,  463,
  464,  465,  466,  467,  468,  469,  470,  471,
  472,  473,  474,  475,  476,  477,  478,  479,
  480,  481,  482,  483,  484,  485,  486,  487,
  488,  489,  490,  491,  492,  493,  494,  495,
  496,  498,  499,  500,  501,  502,  503,  504,
  505,  506,  507,  508,  509,  510,  511,  512,
  513,  514,  515,  516,  517,  518,  519,  520,
  521,  522,  523,  525,  526,  527,  528,  529,
  530,  531,  532,  533,  534,  535,  536,  537,
  538,  539,  540,  541,  542,  544,  545,  546,
  547,  548,  549,  550,  551,  552,  553,  554,
  555,  556,  557,  558,  560,  561,  562,  563,
  564,  565,  566,  567,  568,  569,  570,  571,
  572,  574,  575,  576,  577,  578,  579,  580,
  581,  582,  583,  584,  585,  587,  588,  589,
  590,  591,  592,  593,  594,  595,  596,  597,
  599,  600,  601,  602,  603,  604,  605,  606,
  607,  608,  610,  611,  612,  613,  614,  615,
  616,  617,  618,  620,  621,  622,  623,  624,
  625,  626,  627,  628,  630,  631,  632,  633,
  634,  635,  636,  637,  639,  640,  641,  642,
  643,  644,  645,  646,  648,  649,  650,  651,
  652,  653,  654,  656,  657,  658,  659,  660,
  661,  662,  664,  665,  666,  667,  668,  669,
  670,  672,  673,  674,  675,  676,  677,  678,
  680,  681,  682,  683,  684,  685,  687,  688,
  689,  690,  691,  692,  693,  695,  696,  697,
  698,  699,  700,  702,  703,  704,  705,  706,
  708,  709,  710,  711,  712,  713,  715,  716,
  717,  718,  719,  720,  722,  723,  724,  725,
  726,  728,  729,  730,  731,  732,  733,  735,
  736,  737,  738,  739,  741,  742,  743,  744,
  745,  747,  748,  749,  750,  751,  753,  754,
  755,  756,  757,  759,  760,  761,  762,  763,
  765,  766,  767,  768,  770,  771,  772,  773,
  774,  776,  777,  778,  779,  780,  782,  783,
  784,  785,  787,  788,  789,  790,  792,  793,
  794,  795,  796,  798,  799,  800,  801,  803,
  804,  805,  806,  808,  809,  810,  811,  813,
  814,  815,  816,  818,  819,  820,  821,  823,
  824,  825,  826,  828,  829,  830,  831,  833,
  834,  835,  836,  838,  839,  840,  841,  843,
  844,  845,  846,  848,  849,  850,  851,  853,
  854,  855,  857,  858,  859,  860,  862,  863,
  864,  866,  867,  868,  869,  871,  872,  873,
  874,  876,  877,  878,  880,  881,  882,  883,
  885,  886,  887,  889,  890,  891,  893,  894,
  895,  896,  898,  899,  900,  902,  903,  904,
  906,  907,  908,  909,  911,  912,  913,  915,
  916,  917,  919,  920,  921,  923,  924,  925,
  927,  928,  929,  931,  932,  933,  935,  936,
  937,  938,  940,  941,  942,  944,  945,  946,
  948,  949,  950,  952,  953,  955,  956,  957,
  959,  960,  961,  963,  964,  965,  967,  968,
  969,  971,  972,  973,  975,  976,  977,  979,
  980,  981,  983,  984,  986,  987,  988,  990,
  991,  992,  994,  995,  996,  998,  999, 1001,
  1002, 1003, 1005, 1006, 1007, 1009, 1010, 1012,
  1013, 1014, 1016, 1017, 1018, 1020, 1021, 1023
};

static const WebRtc_Word16 kIndicatorTable[17] = {
  0, 2017, 3809, 5227, 6258, 6963, 7424, 7718,
  7901, 8014, 8084, 8126, 8152, 8168, 8177, 8183, 8187
};

// hybrib Hanning & flat window
static const WebRtc_Word16 kBlocks80w128x[128] = {
  0,    536,   1072,   1606,   2139,   2669,   3196,   3720,   4240,   4756,   5266,
  5771,   6270,   6762,   7246,   7723,   8192,   8652,   9102,   9543,   9974,  10394,
  10803,  11200,  11585,  11958,  12318,  12665,  12998,  13318,  13623,  13913,  14189,
  14449,  14694,  14924,  15137,  15334,  15515,  15679,  15826,  15956,  16069,  16165,
  16244,  16305,  16349,  16375,  16384,  16384,  16384,  16384,  16384,  16384,  16384,
  16384,  16384,  16384,  16384,  16384,  16384,  16384,  16384,  16384,  16384,  16384,
  16384,  16384,  16384,  16384,  16384,  16384,  16384,  16384,  16384,  16384,  16384,
  16384,  16384,  16384,  16384,  16375,  16349,  16305,  16244,  16165,  16069,  15956,
  15826,  15679,  15515,  15334,  15137,  14924,  14694,  14449,  14189,  13913,  13623,
  13318,  12998,  12665,  12318,  11958,  11585,  11200,  10803,  10394,   9974,   9543,
  9102,   8652,   8192,   7723,   7246,   6762,   6270,   5771,   5266,   4756,   4240,
  3720,   3196,   2669,   2139,   1606,   1072,    536
};

// hybrib Hanning & flat window
static const WebRtc_Word16 kBlocks160w256x[256] = {
  0,   268,   536,   804,  1072,  1339,  1606,  1872,
  2139,  2404,  2669,  2933,  3196,  3459,  3720,  3981,
  4240,  4499,  4756,  5012,  5266,  5520,  5771,  6021,
  6270,  6517,  6762,  7005,  7246,  7486,  7723,  7959,
  8192,  8423,  8652,  8878,  9102,  9324,  9543,  9760,
  9974, 10185, 10394, 10600, 10803, 11003, 11200, 11394,
  11585, 11773, 11958, 12140, 12318, 12493, 12665, 12833,
  12998, 13160, 13318, 13472, 13623, 13770, 13913, 14053,
  14189, 14321, 14449, 14574, 14694, 14811, 14924, 15032,
  15137, 15237, 15334, 15426, 15515, 15599, 15679, 15754,
  15826, 15893, 15956, 16015, 16069, 16119, 16165, 16207,
  16244, 16277, 16305, 16329, 16349, 16364, 16375, 16382,
  16384, 16384, 16384, 16384, 16384, 16384, 16384, 16384,
  16384, 16384, 16384, 16384, 16384, 16384, 16384, 16384,
  16384, 16384, 16384, 16384, 16384, 16384, 16384, 16384,
  16384, 16384, 16384, 16384, 16384, 16384, 16384, 16384,
  16384, 16384, 16384, 16384, 16384, 16384, 16384, 16384,
  16384, 16384, 16384, 16384, 16384, 16384, 16384, 16384,
  16384, 16384, 16384, 16384, 16384, 16384, 16384, 16384,
  16384, 16384, 16384, 16384, 16384, 16384, 16384, 16384,
  16384, 16382, 16375, 16364, 16349, 16329, 16305, 16277,
  16244, 16207, 16165, 16119, 16069, 16015, 15956, 15893,
  15826, 15754, 15679, 15599, 15515, 15426, 15334, 15237,
  15137, 15032, 14924, 14811, 14694, 14574, 14449, 14321,
  14189, 14053, 13913, 13770, 13623, 13472, 13318, 13160,
  12998, 12833, 12665, 12493, 12318, 12140, 11958, 11773,
  11585, 11394, 11200, 11003, 10803, 10600, 10394, 10185,
  9974,  9760,  9543,  9324,  9102,  8878,  8652,  8423,
  8192,  7959,  7723,  7486,  7246,  7005,  6762,  6517,
  6270,  6021,  5771,  5520,  5266,  5012,  4756,  4499,
  4240,  3981,  3720,  3459,  3196,  2933,  2669,  2404,
  2139,  1872,  1606,  1339,  1072,   804,   536,   268
};

// Gain factor1 table: Input value in Q8 and output value in Q13
// original floating point code
//  if (gain > blim) {
//    factor1 = 1.0 + 1.3 * (gain - blim);
//    if (gain * factor1 > 1.0) {
//      factor1 = 1.0 / gain;
//    }
//  } else {
//    factor1 = 1.0;
//  }
static const WebRtc_Word16 kFactor1Table[257] = {
  8192, 8192, 8192, 8192, 8192, 8192, 8192,
  8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192,
  8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192,
  8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192,
  8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192,
  8192, 8192, 8233, 8274, 8315, 8355, 8396, 8436, 8475, 8515, 8554, 8592, 8631, 8669,
  8707, 8745, 8783, 8820, 8857, 8894, 8931, 8967, 9003, 9039, 9075, 9111, 9146, 9181,
  9216, 9251, 9286, 9320, 9354, 9388, 9422, 9456, 9489, 9523, 9556, 9589, 9622, 9655,
  9687, 9719, 9752, 9784, 9816, 9848, 9879, 9911, 9942, 9973, 10004, 10035, 10066,
  10097, 10128, 10158, 10188, 10218, 10249, 10279, 10308, 10338, 10368, 10397, 10426,
  10456, 10485, 10514, 10543, 10572, 10600, 10629, 10657, 10686, 10714, 10742, 10770,
  10798, 10826, 10854, 10882, 10847, 10810, 10774, 10737, 10701, 10666, 10631, 10596,
  10562, 10527, 10494, 10460, 10427, 10394, 10362, 10329, 10297, 10266, 10235, 10203,
  10173, 10142, 10112, 10082, 10052, 10023, 9994, 9965, 9936, 9908, 9879, 9851, 9824,
  9796, 9769, 9742, 9715, 9689, 9662, 9636, 9610, 9584, 9559, 9534, 9508, 9484, 9459,
  9434, 9410, 9386, 9362, 9338, 9314, 9291, 9268, 9245, 9222, 9199, 9176, 9154, 9132,
  9110, 9088, 9066, 9044, 9023, 9002, 8980, 8959, 8939, 8918, 8897, 8877, 8857, 8836,
  8816, 8796, 8777, 8757, 8738, 8718, 8699, 8680, 8661, 8642, 8623, 8605, 8586, 8568,
  8550, 8532, 8514, 8496, 8478, 8460, 8443, 8425, 8408, 8391, 8373, 8356, 8339, 8323,
  8306, 8289, 8273, 8256, 8240, 8224, 8208, 8192
};

// For Factor2 tables
// original floating point code
// if (gain > blim) {
//   factor2 = 1.0;
// } else {
//   factor2 = 1.0 - 0.3 * (blim - gain);
//   if (gain <= inst->denoiseBound) {
//     factor2 = 1.0 - 0.3 * (blim - inst->denoiseBound);
//   }
// }
//
// Gain factor table: Input value in Q8 and output value in Q13
static const WebRtc_Word16 kFactor2Aggressiveness1[257] = {
  7577, 7577, 7577, 7577, 7577, 7577,
  7577, 7577, 7577, 7577, 7577, 7577, 7577, 7577, 7577, 7577, 7577, 7596, 7614, 7632,
  7650, 7667, 7683, 7699, 7715, 7731, 7746, 7761, 7775, 7790, 7804, 7818, 7832, 7845,
  7858, 7871, 7884, 7897, 7910, 7922, 7934, 7946, 7958, 7970, 7982, 7993, 8004, 8016,
  8027, 8038, 8049, 8060, 8070, 8081, 8091, 8102, 8112, 8122, 8132, 8143, 8152, 8162,
  8172, 8182, 8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192,
  8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192,
  8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192,
  8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192,
  8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192,
  8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192,
  8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192,
  8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192,
  8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192,
  8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192,
  8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192,
  8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192,
  8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192,
  8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192
};

// Gain factor table: Input value in Q8 and output value in Q13
static const WebRtc_Word16 kFactor2Aggressiveness2[257] = {
  7270, 7270, 7270, 7270, 7270, 7306,
  7339, 7369, 7397, 7424, 7448, 7472, 7495, 7517, 7537, 7558, 7577, 7596, 7614, 7632,
  7650, 7667, 7683, 7699, 7715, 7731, 7746, 7761, 7775, 7790, 7804, 7818, 7832, 7845,
  7858, 7871, 7884, 7897, 7910, 7922, 7934, 7946, 7958, 7970, 7982, 7993, 8004, 8016,
  8027, 8038, 8049, 8060, 8070, 8081, 8091, 8102, 8112, 8122, 8132, 8143, 8152, 8162,
  8172, 8182, 8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192,
  8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192,
  8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192,
  8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192,
  8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192,
  8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192,
  8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192,
  8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192,
  8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192,
  8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192,
  8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192,
  8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192,
  8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192,
  8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192
};

// Gain factor table: Input value in Q8 and output value in Q13
static const WebRtc_Word16 kFactor2Aggressiveness3[257] = {
  7184, 7184, 7184, 7229, 7270, 7306,
  7339, 7369, 7397, 7424, 7448, 7472, 7495, 7517, 7537, 7558, 7577, 7596, 7614, 7632,
  7650, 7667, 7683, 7699, 7715, 7731, 7746, 7761, 7775, 7790, 7804, 7818, 7832, 7845,
  7858, 7871, 7884, 7897, 7910, 7922, 7934, 7946, 7958, 7970, 7982, 7993, 8004, 8016,
  8027, 8038, 8049, 8060, 8070, 8081, 8091, 8102, 8112, 8122, 8132, 8143, 8152, 8162,
  8172, 8182, 8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192,
  8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192,
  8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192,
  8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192,
  8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192,
  8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192,
  8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192,
  8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192,
  8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192,
  8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192,
  8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192,
  8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192,
  8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192,
  8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192, 8192
};

// sum of log2(i) from table index to inst->anaLen2 in Q5
// Note that the first table value is invalid, since log2(0) = -infinity
static const WebRtc_Word16 kSumLogIndex[66] = {
  0,  22917,  22917,  22885,  22834,  22770,  22696,  22613,
  22524,  22428,  22326,  22220,  22109,  21994,  21876,  21754,
  21629,  21501,  21370,  21237,  21101,  20963,  20822,  20679,
  20535,  20388,  20239,  20089,  19937,  19783,  19628,  19470,
  19312,  19152,  18991,  18828,  18664,  18498,  18331,  18164,
  17994,  17824,  17653,  17480,  17306,  17132,  16956,  16779,
  16602,  16423,  16243,  16063,  15881,  15699,  15515,  15331,
  15146,  14960,  14774,  14586,  14398,  14209,  14019,  13829,
  13637,  13445
};

// sum of log2(i)^2 from table index to inst->anaLen2 in Q2
// Note that the first table value is invalid, since log2(0) = -infinity
static const WebRtc_Word16 kSumSquareLogIndex[66] = {
  0,  16959,  16959,  16955,  16945,  16929,  16908,  16881,
  16850,  16814,  16773,  16729,  16681,  16630,  16575,  16517,
  16456,  16392,  16325,  16256,  16184,  16109,  16032,  15952,
  15870,  15786,  15700,  15612,  15521,  15429,  15334,  15238,
  15140,  15040,  14938,  14834,  14729,  14622,  14514,  14404,
  14292,  14179,  14064,  13947,  13830,  13710,  13590,  13468,
  13344,  13220,  13094,  12966,  12837,  12707,  12576,  12444,
  12310,  12175,  12039,  11902,  11763,  11624,  11483,  11341,
  11198,  11054
};

// log2(table index) in Q12
// Note that the first table value is invalid, since log2(0) = -infinity
static const WebRtc_Word16 kLogIndex[129] = {
  0,      0,   4096,   6492,   8192,   9511,  10588,  11499,
  12288,  12984,  13607,  14170,  14684,  15157,  15595,  16003,
  16384,  16742,  17080,  17400,  17703,  17991,  18266,  18529,
  18780,  19021,  19253,  19476,  19691,  19898,  20099,  20292,
  20480,  20662,  20838,  21010,  21176,  21338,  21496,  21649,
  21799,  21945,  22087,  22226,  22362,  22495,  22625,  22752,
  22876,  22998,  23117,  23234,  23349,  23462,  23572,  23680,
  23787,  23892,  23994,  24095,  24195,  24292,  24388,  24483,
  24576,  24668,  24758,  24847,  24934,  25021,  25106,  25189,
  25272,  25354,  25434,  25513,  25592,  25669,  25745,  25820,
  25895,  25968,  26041,  26112,  26183,  26253,  26322,  26390,
  26458,  26525,  26591,  26656,  26721,  26784,  26848,  26910,
  26972,  27033,  27094,  27154,  27213,  27272,  27330,  27388,
  27445,  27502,  27558,  27613,  27668,  27722,  27776,  27830,
  27883,  27935,  27988,  28039,  28090,  28141,  28191,  28241,
  28291,  28340,  28388,  28437,  28484,  28532,  28579,  28626,
  28672
};

// determinant of estimation matrix in Q0 corresponding to the log2 tables above
// Note that the first table value is invalid, since log2(0) = -infinity
static const WebRtc_Word16 kDeterminantEstMatrix[66] = {
  0,  29814,  25574,  22640,  20351,  18469,  16873,  15491,
  14277,  13199,  12233,  11362,  10571,   9851,   9192,   8587,
  8030,   7515,   7038,   6596,   6186,   5804,   5448,   5115,
  4805,   4514,   4242,   3988,   3749,   3524,   3314,   3116,
  2930,   2755,   2590,   2435,   2289,   2152,   2022,   1900,
  1785,   1677,   1575,   1478,   1388,   1302,   1221,   1145,
  1073,   1005,    942,    881,    825,    771,    721,    674,
  629,    587,    547,    510,    475,    442,    411,    382,
  355,    330
};

// Declare function pointers.
NoiseEstimation WebRtcNsx_NoiseEstimation;
PrepareSpectrum WebRtcNsx_PrepareSpectrum;
SynthesisUpdate WebRtcNsx_SynthesisUpdate;
AnalysisUpdate WebRtcNsx_AnalysisUpdate;
Denormalize WebRtcNsx_Denormalize;
CreateComplexBuffer WebRtcNsx_CreateComplexBuffer;

// Update the noise estimation information.
static void UpdateNoiseEstimate(NsxInst_t* inst, int offset) {
  WebRtc_Word32 tmp32no1 = 0;
  WebRtc_Word32 tmp32no2 = 0;
  WebRtc_Word16 tmp16 = 0;
  const WebRtc_Word16 kExp2Const = 11819; // Q13

  int i = 0;

  tmp16 = WebRtcSpl_MaxValueW16(inst->noiseEstLogQuantile + offset,
                                   inst->magnLen);
  // Guarantee a Q-domain as high as possible and still fit in int16
  inst->qNoise = 14 - (int) WEBRTC_SPL_MUL_16_16_RSFT_WITH_ROUND(
                   kExp2Const, tmp16, 21);
  for (i = 0; i < inst->magnLen; i++) {
    // inst->quantile[i]=exp(inst->lquantile[offset+i]);
    // in Q21
    tmp32no2 = WEBRTC_SPL_MUL_16_16(kExp2Const,
                                    inst->noiseEstLogQuantile[offset + i]);
    tmp32no1 = (0x00200000 | (tmp32no2 & 0x001FFFFF)); // 2^21 + frac
    tmp16 = (WebRtc_Word16) WEBRTC_SPL_RSHIFT_W32(tmp32no2, 21);
    tmp16 -= 21;// shift 21 to get result in Q0
    tmp16 += (WebRtc_Word16) inst->qNoise; //shift to get result in Q(qNoise)
    if (tmp16 < 0) {
      tmp32no1 = WEBRTC_SPL_RSHIFT_W32(tmp32no1, -tmp16);
    } else {
      tmp32no1 = WEBRTC_SPL_LSHIFT_W32(tmp32no1, tmp16);
    }
    inst->noiseEstQuantile[i] = WebRtcSpl_SatW32ToW16(tmp32no1);
  }
}

// Noise Estimation
static void NoiseEstimationC(NsxInst_t* inst,
                             uint16_t* magn,
                             uint32_t* noise,
                             int16_t* q_noise) {
  WebRtc_Word16 lmagn[HALF_ANAL_BLOCKL], counter, countDiv;
  WebRtc_Word16 countProd, delta, zeros, frac;
  WebRtc_Word16 log2, tabind, logval, tmp16, tmp16no1, tmp16no2;
  const int16_t log2_const = 22713; // Q15
  const int16_t width_factor = 21845;

  int i, s, offset;

  tabind = inst->stages - inst->normData;
  assert(tabind < 9);
  assert(tabind > -9);
  if (tabind < 0) {
    logval = -WebRtcNsx_kLogTable[-tabind];
  } else {
    logval = WebRtcNsx_kLogTable[tabind];
  }

  // lmagn(i)=log(magn(i))=log(2)*log2(magn(i))
  // magn is in Q(-stages), and the real lmagn values are:
  // real_lmagn(i)=log(magn(i)*2^stages)=log(magn(i))+log(2^stages)
  // lmagn in Q8
  for (i = 0; i < inst->magnLen; i++) {
    if (magn[i]) {
      zeros = WebRtcSpl_NormU32((WebRtc_UWord32)magn[i]);
      frac = (WebRtc_Word16)((((WebRtc_UWord32)magn[i] << zeros)
                              & 0x7FFFFFFF) >> 23);
      // log2(magn(i))
      assert(frac < 256);
      log2 = (WebRtc_Word16)(((31 - zeros) << 8)
                             + WebRtcNsx_kLogTableFrac[frac]);
      // log2(magn(i))*log(2)
      lmagn[i] = (WebRtc_Word16)WEBRTC_SPL_MUL_16_16_RSFT(log2, log2_const, 15);
      // + log(2^stages)
      lmagn[i] += logval;
    } else {
      lmagn[i] = logval;//0;
    }
  }

  // loop over simultaneous estimates
  for (s = 0; s < SIMULT; s++) {
    offset = s * inst->magnLen;

    // Get counter values from state
    counter = inst->noiseEstCounter[s];
    assert(counter < 201);
    countDiv = WebRtcNsx_kCounterDiv[counter];
    countProd = (WebRtc_Word16)WEBRTC_SPL_MUL_16_16(counter, countDiv);

    // quant_est(...)
    for (i = 0; i < inst->magnLen; i++) {
      // compute delta
      if (inst->noiseEstDensity[offset + i] > 512) {
        // Get the value for delta by shifting intead of dividing.
        int factor = WebRtcSpl_NormW16(inst->noiseEstDensity[offset + i]);
        delta = (int16_t)(FACTOR_Q16 >> (14 - factor));
      } else {
        delta = FACTOR_Q7;
        if (inst->blockIndex < END_STARTUP_LONG) {
          // Smaller step size during startup. This prevents from using
          // unrealistic values causing overflow.
          delta = FACTOR_Q7_STARTUP;
        }
      }

      // update log quantile estimate
      tmp16 = (WebRtc_Word16)WEBRTC_SPL_MUL_16_16_RSFT(delta, countDiv, 14);
      if (lmagn[i] > inst->noiseEstLogQuantile[offset + i]) {
        // +=QUANTILE*delta/(inst->counter[s]+1) QUANTILE=0.25, =1 in Q2
        // CounterDiv=1/(inst->counter[s]+1) in Q15
        tmp16 += 2;
        tmp16no1 = WEBRTC_SPL_RSHIFT_W16(tmp16, 2);
        inst->noiseEstLogQuantile[offset + i] += tmp16no1;
      } else {
        tmp16 += 1;
        tmp16no1 = WEBRTC_SPL_RSHIFT_W16(tmp16, 1);
        // *(1-QUANTILE), in Q2 QUANTILE=0.25, 1-0.25=0.75=3 in Q2
        tmp16no2 = (WebRtc_Word16)WEBRTC_SPL_MUL_16_16_RSFT(tmp16no1, 3, 1);
        inst->noiseEstLogQuantile[offset + i] -= tmp16no2;
        if (inst->noiseEstLogQuantile[offset + i] < logval) {
          // This is the smallest fixed point representation we can
          // have, hence we limit the output.
          inst->noiseEstLogQuantile[offset + i] = logval;
        }
      }

      // update density estimate
      if (WEBRTC_SPL_ABS_W16(lmagn[i] - inst->noiseEstLogQuantile[offset + i])
          < WIDTH_Q8) {
        tmp16no1 = (WebRtc_Word16)WEBRTC_SPL_MUL_16_16_RSFT_WITH_ROUND(
                     inst->noiseEstDensity[offset + i], countProd, 15);
        tmp16no2 = (WebRtc_Word16)WEBRTC_SPL_MUL_16_16_RSFT_WITH_ROUND(
                     width_factor, countDiv, 15);
        inst->noiseEstDensity[offset + i] = tmp16no1 + tmp16no2;
      }
    } // end loop over magnitude spectrum

    if (counter >= END_STARTUP_LONG) {
      inst->noiseEstCounter[s] = 0;
      if (inst->blockIndex >= END_STARTUP_LONG) {
        UpdateNoiseEstimate(inst, offset);
      }
    }
    inst->noiseEstCounter[s]++;

  } // end loop over simultaneous estimates

  // Sequentially update the noise during startup
  if (inst->blockIndex < END_STARTUP_LONG) {
    UpdateNoiseEstimate(inst, offset);
  }

  for (i = 0; i < inst->magnLen; i++) {
    noise[i] = (WebRtc_UWord32)(inst->noiseEstQuantile[i]); // Q(qNoise)
  }
  (*q_noise) = (WebRtc_Word16)inst->qNoise;
}

// Filter the data in the frequency domain, and create spectrum.
static void PrepareSpectrumC(NsxInst_t* inst, int16_t* freq_buf) {
  int i = 0, j = 0;
  int16_t tmp16 = 0;

  for (i = 0; i < inst->magnLen; i++) {
    inst->real[i] = (WebRtc_Word16)WEBRTC_SPL_MUL_16_16_RSFT(inst->real[i],
        (WebRtc_Word16)(inst->noiseSupFilter[i]), 14); // Q(normData-stages)
    inst->imag[i] = (WebRtc_Word16)WEBRTC_SPL_MUL_16_16_RSFT(inst->imag[i],
        (WebRtc_Word16)(inst->noiseSupFilter[i]), 14); // Q(normData-stages)
  }

  freq_buf[0] = inst->real[0];
  freq_buf[1] = -inst->imag[0];
  for (i = 1, j = 2; i < inst->anaLen2; i += 1, j += 2) {
    tmp16 = (inst->anaLen << 1) - j;
    freq_buf[j] = inst->real[i];
    freq_buf[j + 1] = -inst->imag[i];
    freq_buf[tmp16] = inst->real[i];
    freq_buf[tmp16 + 1] = inst->imag[i];
  }
  freq_buf[inst->anaLen] = inst->real[inst->anaLen2];
  freq_buf[inst->anaLen + 1] = -inst->imag[inst->anaLen2];
}

// Denormalize the input buffer.
static __inline void DenormalizeC(NsxInst_t* inst, int16_t* in, int factor) {
  int i = 0, j = 0;
  int32_t tmp32 = 0;
  for (i = 0, j = 0; i < inst->anaLen; i += 1, j += 2) {
    tmp32 = WEBRTC_SPL_SHIFT_W32((WebRtc_Word32)in[j],
                                 factor - inst->normData);
    inst->real[i] = WebRtcSpl_SatW32ToW16(tmp32); // Q0
  }
}

// For the noise supression process, synthesis, read out fully processed
// segment, and update synthesis buffer.
static void SynthesisUpdateC(NsxInst_t* inst,
                             int16_t* out_frame,
                             int16_t gain_factor) {
  int i = 0;
  int16_t tmp16a = 0;
  int16_t tmp16b = 0;
  int32_t tmp32 = 0;

  // synthesis
  for (i = 0; i < inst->anaLen; i++) {
    tmp16a = (int16_t)WEBRTC_SPL_MUL_16_16_RSFT_WITH_ROUND(
                 inst->window[i], inst->real[i], 14); // Q0, window in Q14
    tmp32 = WEBRTC_SPL_MUL_16_16_RSFT_WITH_ROUND(tmp16a, gain_factor, 13); // Q0
    // Down shift with rounding
    tmp16b = WebRtcSpl_SatW32ToW16(tmp32); // Q0
    inst->synthesisBuffer[i] = WEBRTC_SPL_ADD_SAT_W16(inst->synthesisBuffer[i],
                                                      tmp16b); // Q0
  }

  // read out fully processed segment
  for (i = 0; i < inst->blockLen10ms; i++) {
    out_frame[i] = inst->synthesisBuffer[i]; // Q0
  }

  // update synthesis buffer
  WEBRTC_SPL_MEMCPY_W16(inst->synthesisBuffer,
                        inst->synthesisBuffer + inst->blockLen10ms,
                        inst->anaLen - inst->blockLen10ms);
  WebRtcSpl_ZerosArrayW16(inst->synthesisBuffer
      + inst->anaLen - inst->blockLen10ms, inst->blockLen10ms);
}

// Update analysis buffer for lower band, and window data before FFT.
static void AnalysisUpdateC(NsxInst_t* inst,
                            int16_t* out,
                            int16_t* new_speech) {
  int i = 0;

  // For lower band update analysis buffer.
  WEBRTC_SPL_MEMCPY_W16(inst->analysisBuffer,
                        inst->analysisBuffer + inst->blockLen10ms,
                        inst->anaLen - inst->blockLen10ms);
  WEBRTC_SPL_MEMCPY_W16(inst->analysisBuffer
      + inst->anaLen - inst->blockLen10ms, new_speech, inst->blockLen10ms);

  // Window data before FFT.
  for (i = 0; i < inst->anaLen; i++) {
    out[i] = (int16_t)WEBRTC_SPL_MUL_16_16_RSFT_WITH_ROUND(
               inst->window[i], inst->analysisBuffer[i], 14); // Q0
  }
}

// Create a complex number buffer (out[]) as the intput (in[]) interleaved with
// zeros, and normalize it.
static __inline void CreateComplexBufferC(NsxInst_t* inst,
                                          int16_t* in,
                                          int16_t* out) {
  int i = 0, j = 0;
  for (i = 0, j = 0; i < inst->anaLen; i += 1, j += 2) {
    out[j] = WEBRTC_SPL_LSHIFT_W16(in[i], inst->normData); // Q(normData)
    out[j + 1] = 0; // Insert zeros in imaginary part
  }
}

void WebRtcNsx_CalcParametricNoiseEstimate(NsxInst_t* inst,
                                           WebRtc_Word16 pink_noise_exp_avg,
                                           WebRtc_Word32 pink_noise_num_avg,
                                           int freq_index,
                                           WebRtc_UWord32* noise_estimate,
                                           WebRtc_UWord32* noise_estimate_avg) {
  WebRtc_Word32 tmp32no1 = 0;
  WebRtc_Word32 tmp32no2 = 0;

  WebRtc_Word16 int_part = 0;
  WebRtc_Word16 frac_part = 0;

  // Use pink noise estimate
  // noise_estimate = 2^(pinkNoiseNumerator + pinkNoiseExp * log2(j))
  assert(freq_index >= 0);
  assert(freq_index < 129);
  tmp32no2 = WEBRTC_SPL_MUL_16_16(pink_noise_exp_avg, kLogIndex[freq_index]); // Q26
  tmp32no2 = WEBRTC_SPL_RSHIFT_W32(tmp32no2, 15); // Q11
  tmp32no1 = pink_noise_num_avg - tmp32no2; // Q11

  // Calculate output: 2^tmp32no1
  // Output in Q(minNorm-stages)
  tmp32no1 += WEBRTC_SPL_LSHIFT_W32((WebRtc_Word32)(inst->minNorm - inst->stages), 11);
  if (tmp32no1 > 0) {
    int_part = (WebRtc_Word16)WEBRTC_SPL_RSHIFT_W32(tmp32no1, 11);
    frac_part = (WebRtc_Word16)(tmp32no1 & 0x000007ff); // Q11
    // Piecewise linear approximation of 'b' in
    // 2^(int_part+frac_part) = 2^int_part * (1 + b)
    // 'b' is given in Q11 and below stored in frac_part.
    if (WEBRTC_SPL_RSHIFT_W16(frac_part, 10)) {
      // Upper fractional part
      tmp32no2 = WEBRTC_SPL_MUL_16_16(2048 - frac_part, 1244); // Q21
      tmp32no2 = 2048 - WEBRTC_SPL_RSHIFT_W32(tmp32no2, 10);
    } else {
      // Lower fractional part
      tmp32no2 = WEBRTC_SPL_RSHIFT_W32(WEBRTC_SPL_MUL_16_16(frac_part, 804), 10);
    }
    // Shift fractional part to Q(minNorm-stages)
    tmp32no2 = WEBRTC_SPL_SHIFT_W32(tmp32no2, int_part - 11);
    *noise_estimate_avg = WEBRTC_SPL_LSHIFT_U32(1, int_part) + (WebRtc_UWord32)tmp32no2;
    // Scale up to initMagnEst, which is not block averaged
    *noise_estimate = (*noise_estimate_avg) * (WebRtc_UWord32)(inst->blockIndex + 1);
  }
}

// Initialize state
WebRtc_Word32 WebRtcNsx_InitCore(NsxInst_t* inst, WebRtc_UWord32 fs) {
  int i;

  //check for valid pointer
  if (inst == NULL) {
    return -1;
  }
  //

  // Initialization of struct
  if (fs == 8000 || fs == 16000 || fs == 32000) {
    inst->fs = fs;
  } else {
    return -1;
  }

  if (fs == 8000) {
    inst->blockLen10ms = 80;
    inst->anaLen = 128;
    inst->stages = 7;
    inst->window = kBlocks80w128x;
    inst->thresholdLogLrt = 131072; //default threshold for LRT feature
    inst->maxLrt = 0x0040000;
    inst->minLrt = 52429;
  } else if (fs == 16000) {
    inst->blockLen10ms = 160;
    inst->anaLen = 256;
    inst->stages = 8;
    inst->window = kBlocks160w256x;
    inst->thresholdLogLrt = 212644; //default threshold for LRT feature
    inst->maxLrt = 0x0080000;
    inst->minLrt = 104858;
  } else if (fs == 32000) {
    inst->blockLen10ms = 160;
    inst->anaLen = 256;
    inst->stages = 8;
    inst->window = kBlocks160w256x;
    inst->thresholdLogLrt = 212644; //default threshold for LRT feature
    inst->maxLrt = 0x0080000;
    inst->minLrt = 104858;
  }
  inst->anaLen2 = WEBRTC_SPL_RSHIFT_W16(inst->anaLen, 1);
  inst->magnLen = inst->anaLen2 + 1;

  WebRtcSpl_ZerosArrayW16(inst->analysisBuffer, ANAL_BLOCKL_MAX);
  WebRtcSpl_ZerosArrayW16(inst->synthesisBuffer, ANAL_BLOCKL_MAX);

  // for HB processing
  WebRtcSpl_ZerosArrayW16(inst->dataBufHBFX, ANAL_BLOCKL_MAX);
  // for quantile noise estimation
  WebRtcSpl_ZerosArrayW16(inst->noiseEstQuantile, HALF_ANAL_BLOCKL);
  for (i = 0; i < SIMULT * HALF_ANAL_BLOCKL; i++) {
    inst->noiseEstLogQuantile[i] = 2048; // Q8
    inst->noiseEstDensity[i] = 153; // Q9
  }
  for (i = 0; i < SIMULT; i++) {
    inst->noiseEstCounter[i] = (WebRtc_Word16)(END_STARTUP_LONG * (i + 1)) / SIMULT;
  }

  // Initialize suppression filter with ones
  WebRtcSpl_MemSetW16((WebRtc_Word16*)inst->noiseSupFilter, 16384, HALF_ANAL_BLOCKL);

  // Set the aggressiveness: default
  inst->aggrMode = 0;

  //initialize variables for new method
  inst->priorNonSpeechProb = 8192; // Q14(0.5) prior probability for speech/noise
  for (i = 0; i < HALF_ANAL_BLOCKL; i++) {
    inst->prevMagnU16[i] = 0;
    inst->prevNoiseU32[i] = 0; //previous noise-spectrum
    inst->logLrtTimeAvgW32[i] = 0; //smooth LR ratio
    inst->avgMagnPause[i] = 0; //conservative noise spectrum estimate
    inst->initMagnEst[i] = 0; //initial average magnitude spectrum
  }

  //feature quantities
  inst->thresholdSpecDiff = 50; //threshold for difference feature: determined on-line
  inst->thresholdSpecFlat = 20480; //threshold for flatness: determined on-line
  inst->featureLogLrt = inst->thresholdLogLrt; //average LRT factor (= threshold)
  inst->featureSpecFlat = inst->thresholdSpecFlat; //spectral flatness (= threshold)
  inst->featureSpecDiff = inst->thresholdSpecDiff; //spectral difference (= threshold)
  inst->weightLogLrt = 6; //default weighting par for LRT feature
  inst->weightSpecFlat = 0; //default weighting par for spectral flatness feature
  inst->weightSpecDiff = 0; //default weighting par for spectral difference feature

  inst->curAvgMagnEnergy = 0; //window time-average of input magnitude spectrum
  inst->timeAvgMagnEnergy = 0; //normalization for spectral difference
  inst->timeAvgMagnEnergyTmp = 0; //normalization for spectral difference

  //histogram quantities: used to estimate/update thresholds for features
  WebRtcSpl_ZerosArrayW16(inst->histLrt, HIST_PAR_EST);
  WebRtcSpl_ZerosArrayW16(inst->histSpecDiff, HIST_PAR_EST);
  WebRtcSpl_ZerosArrayW16(inst->histSpecFlat, HIST_PAR_EST);

  inst->blockIndex = -1; //frame counter

  //inst->modelUpdate    = 500;   //window for update
  inst->modelUpdate = (1 << STAT_UPDATES); //window for update
  inst->cntThresUpdate = 0; //counter feature thresholds updates

  inst->sumMagn = 0;
  inst->magnEnergy = 0;
  inst->prevQMagn = 0;
  inst->qNoise = 0;
  inst->prevQNoise = 0;

  inst->energyIn = 0;
  inst->scaleEnergyIn = 0;

  inst->whiteNoiseLevel = 0;
  inst->pinkNoiseNumerator = 0;
  inst->pinkNoiseExp = 0;
  inst->minNorm = 15; // Start with full scale
  inst->zeroInputSignal = 0;

  //default mode
  WebRtcNsx_set_policy_core(inst, 0);

#ifdef NS_FILEDEBUG
  inst->infile = fopen("indebug.pcm", "wb");
  inst->outfile = fopen("outdebug.pcm", "wb");
  inst->file1 = fopen("file1.pcm", "wb");
  inst->file2 = fopen("file2.pcm", "wb");
  inst->file3 = fopen("file3.pcm", "wb");
  inst->file4 = fopen("file4.pcm", "wb");
  inst->file5 = fopen("file5.pcm", "wb");
#endif

  // Initialize function pointers.
  WebRtcNsx_NoiseEstimation = NoiseEstimationC;
  WebRtcNsx_PrepareSpectrum = PrepareSpectrumC;
  WebRtcNsx_SynthesisUpdate = SynthesisUpdateC;
  WebRtcNsx_AnalysisUpdate = AnalysisUpdateC;
  WebRtcNsx_Denormalize = DenormalizeC;
  WebRtcNsx_CreateComplexBuffer = CreateComplexBufferC;

#ifdef WEBRTC_DETECT_ARM_NEON
    uint64_t features = WebRtc_GetCPUFeaturesARM();
    if ((features & kCPUFeatureNEON) != 0)
    {
        WebRtcNsx_InitNeon();
    }
#elif defined(WEBRTC_ARCH_ARM_NEON)
    WebRtcNsx_InitNeon();
#endif

  inst->initFlag = 1;

  return 0;
}

int WebRtcNsx_set_policy_core(NsxInst_t* inst, int mode) {
  // allow for modes:0,1,2,3
  if (mode < 0 || mode > 3) {
    return -1;
  }

  inst->aggrMode = mode;
  if (mode == 0) {
    inst->overdrive = 256; // Q8(1.0)
    inst->denoiseBound = 8192; // Q14(0.5)
    inst->gainMap = 0; // No gain compensation
  } else if (mode == 1) {
    inst->overdrive = 256; // Q8(1.0)
    inst->denoiseBound = 4096; // Q14(0.25)
    inst->factor2Table = kFactor2Aggressiveness1;
    inst->gainMap = 1;
  } else if (mode == 2) {
    inst->overdrive = 282; // ~= Q8(1.1)
    inst->denoiseBound = 2048; // Q14(0.125)
    inst->factor2Table = kFactor2Aggressiveness2;
    inst->gainMap = 1;
  } else if (mode == 3) {
    inst->overdrive = 320; // Q8(1.25)
    inst->denoiseBound = 1475; // ~= Q14(0.09)
    inst->factor2Table = kFactor2Aggressiveness3;
    inst->gainMap = 1;
  }
  return 0;
}

// Extract thresholds for feature parameters
// histograms are computed over some window_size (given by window_pars)
// thresholds and weights are extracted every window
// flag 0 means update histogram only, flag 1 means compute the thresholds/weights
// threshold and weights are returned in: inst->priorModelPars
void WebRtcNsx_FeatureParameterExtraction(NsxInst_t* inst, int flag) {
  WebRtc_UWord32 tmpU32;
  WebRtc_UWord32 histIndex;
  WebRtc_UWord32 posPeak1SpecFlatFX, posPeak2SpecFlatFX;
  WebRtc_UWord32 posPeak1SpecDiffFX, posPeak2SpecDiffFX;

  WebRtc_Word32 tmp32;
  WebRtc_Word32 fluctLrtFX, thresFluctLrtFX;
  WebRtc_Word32 avgHistLrtFX, avgSquareHistLrtFX, avgHistLrtComplFX;

  WebRtc_Word16 j;
  WebRtc_Word16 numHistLrt;

  int i;
  int useFeatureSpecFlat, useFeatureSpecDiff, featureSum;
  int maxPeak1, maxPeak2;
  int weightPeak1SpecFlat, weightPeak2SpecFlat;
  int weightPeak1SpecDiff, weightPeak2SpecDiff;

  //update histograms
  if (!flag) {
    // LRT
    // Type casting to UWord32 is safe since negative values will not be wrapped to larger
    // values than HIST_PAR_EST
    histIndex = (WebRtc_UWord32)(inst->featureLogLrt);
    if (histIndex < HIST_PAR_EST) {
      inst->histLrt[histIndex]++;
    }
    // Spectral flatness
    // (inst->featureSpecFlat*20)>>10 = (inst->featureSpecFlat*5)>>8
    histIndex = WEBRTC_SPL_RSHIFT_U32(inst->featureSpecFlat * 5, 8);
    if (histIndex < HIST_PAR_EST) {
      inst->histSpecFlat[histIndex]++;
    }
    // Spectral difference
    histIndex = HIST_PAR_EST;
    if (inst->timeAvgMagnEnergy > 0) {
      // Guard against division by zero
      // If timeAvgMagnEnergy == 0 we have no normalizing statistics and
      // therefore can't update the histogram
      histIndex = WEBRTC_SPL_UDIV((inst->featureSpecDiff * 5) >> inst->stages,
                                  inst->timeAvgMagnEnergy);
    }
    if (histIndex < HIST_PAR_EST) {
      inst->histSpecDiff[histIndex]++;
    }
  }

  // extract parameters for speech/noise probability
  if (flag) {
    useFeatureSpecDiff = 1;
    //for LRT feature:
    // compute the average over inst->featureExtractionParams.rangeAvgHistLrt
    avgHistLrtFX = 0;
    avgSquareHistLrtFX = 0;
    numHistLrt = 0;
    for (i = 0; i < BIN_SIZE_LRT; i++) {
      j = (2 * i + 1);
      tmp32 = WEBRTC_SPL_MUL_16_16(inst->histLrt[i], j);
      avgHistLrtFX += tmp32;
      numHistLrt += inst->histLrt[i];
      avgSquareHistLrtFX += WEBRTC_SPL_MUL_32_16(tmp32, j);
    }
    avgHistLrtComplFX = avgHistLrtFX;
    for (; i < HIST_PAR_EST; i++) {
      j = (2 * i + 1);
      tmp32 = WEBRTC_SPL_MUL_16_16(inst->histLrt[i], j);
      avgHistLrtComplFX += tmp32;
      avgSquareHistLrtFX += WEBRTC_SPL_MUL_32_16(tmp32, j);
    }
    fluctLrtFX = WEBRTC_SPL_MUL(avgSquareHistLrtFX, numHistLrt);
    fluctLrtFX -= WEBRTC_SPL_MUL(avgHistLrtFX, avgHistLrtComplFX);
    thresFluctLrtFX = THRES_FLUCT_LRT * numHistLrt;
    // get threshold for LRT feature:
    tmpU32 = (FACTOR_1_LRT_DIFF * (WebRtc_UWord32)avgHistLrtFX);
    if ((fluctLrtFX < thresFluctLrtFX) || (numHistLrt == 0) ||
        (tmpU32 > (WebRtc_UWord32)(100 * numHistLrt))) {
      //very low fluctuation, so likely noise
      inst->thresholdLogLrt = inst->maxLrt;
    } else {
      tmp32 = (WebRtc_Word32)((tmpU32 << (9 + inst->stages)) / numHistLrt /
                              25);
      // check if value is within min/max range
      inst->thresholdLogLrt = WEBRTC_SPL_SAT(inst->maxLrt,
                                             tmp32,
                                             inst->minLrt);
    }
    if (fluctLrtFX < thresFluctLrtFX) {
      // Do not use difference feature if fluctuation of LRT feature is very low:
      // most likely just noise state
      useFeatureSpecDiff = 0;
    }

    // for spectral flatness and spectral difference: compute the main peaks of histogram
    maxPeak1 = 0;
    maxPeak2 = 0;
    posPeak1SpecFlatFX = 0;
    posPeak2SpecFlatFX = 0;
    weightPeak1SpecFlat = 0;
    weightPeak2SpecFlat = 0;

    // peaks for flatness
    for (i = 0; i < HIST_PAR_EST; i++) {
      if (inst->histSpecFlat[i] > maxPeak1) {
        // Found new "first" peak
        maxPeak2 = maxPeak1;
        weightPeak2SpecFlat = weightPeak1SpecFlat;
        posPeak2SpecFlatFX = posPeak1SpecFlatFX;

        maxPeak1 = inst->histSpecFlat[i];
        weightPeak1SpecFlat = inst->histSpecFlat[i];
        posPeak1SpecFlatFX = (WebRtc_UWord32)(2 * i + 1);
      } else if (inst->histSpecFlat[i] > maxPeak2) {
        // Found new "second" peak
        maxPeak2 = inst->histSpecFlat[i];
        weightPeak2SpecFlat = inst->histSpecFlat[i];
        posPeak2SpecFlatFX = (WebRtc_UWord32)(2 * i + 1);
      }
    }

    // for spectral flatness feature
    useFeatureSpecFlat = 1;
    // merge the two peaks if they are close
    if ((posPeak1SpecFlatFX - posPeak2SpecFlatFX < LIM_PEAK_SPACE_FLAT_DIFF)
        && (weightPeak2SpecFlat * LIM_PEAK_WEIGHT_FLAT_DIFF > weightPeak1SpecFlat)) {
      weightPeak1SpecFlat += weightPeak2SpecFlat;
      posPeak1SpecFlatFX = (posPeak1SpecFlatFX + posPeak2SpecFlatFX) >> 1;
    }
    //reject if weight of peaks is not large enough, or peak value too small
    if (weightPeak1SpecFlat < THRES_WEIGHT_FLAT_DIFF || posPeak1SpecFlatFX
        < THRES_PEAK_FLAT) {
      useFeatureSpecFlat = 0;
    } else { // if selected, get the threshold
      // compute the threshold and check if value is within min/max range
      inst->thresholdSpecFlat = WEBRTC_SPL_SAT(MAX_FLAT_Q10, FACTOR_2_FLAT_Q10
                                               * posPeak1SpecFlatFX, MIN_FLAT_Q10); //Q10
    }
    // done with flatness feature

    if (useFeatureSpecDiff) {
      //compute two peaks for spectral difference
      maxPeak1 = 0;
      maxPeak2 = 0;
      posPeak1SpecDiffFX = 0;
      posPeak2SpecDiffFX = 0;
      weightPeak1SpecDiff = 0;
      weightPeak2SpecDiff = 0;
      // peaks for spectral difference
      for (i = 0; i < HIST_PAR_EST; i++) {
        if (inst->histSpecDiff[i] > maxPeak1) {
          // Found new "first" peak
          maxPeak2 = maxPeak1;
          weightPeak2SpecDiff = weightPeak1SpecDiff;
          posPeak2SpecDiffFX = posPeak1SpecDiffFX;

          maxPeak1 = inst->histSpecDiff[i];
          weightPeak1SpecDiff = inst->histSpecDiff[i];
          posPeak1SpecDiffFX = (WebRtc_UWord32)(2 * i + 1);
        } else if (inst->histSpecDiff[i] > maxPeak2) {
          // Found new "second" peak
          maxPeak2 = inst->histSpecDiff[i];
          weightPeak2SpecDiff = inst->histSpecDiff[i];
          posPeak2SpecDiffFX = (WebRtc_UWord32)(2 * i + 1);
        }
      }

      // merge the two peaks if they are close
      if ((posPeak1SpecDiffFX - posPeak2SpecDiffFX < LIM_PEAK_SPACE_FLAT_DIFF)
          && (weightPeak2SpecDiff * LIM_PEAK_WEIGHT_FLAT_DIFF > weightPeak1SpecDiff)) {
        weightPeak1SpecDiff += weightPeak2SpecDiff;
        posPeak1SpecDiffFX = (posPeak1SpecDiffFX + posPeak2SpecDiffFX) >> 1;
      }
      // get the threshold value and check if value is within min/max range
      inst->thresholdSpecDiff = WEBRTC_SPL_SAT(MAX_DIFF, FACTOR_1_LRT_DIFF
                                               * posPeak1SpecDiffFX, MIN_DIFF); //5x bigger
      //reject if weight of peaks is not large enough
      if (weightPeak1SpecDiff < THRES_WEIGHT_FLAT_DIFF) {
        useFeatureSpecDiff = 0;
      }
      // done with spectral difference feature
    }

    // select the weights between the features
    // inst->priorModelPars[4] is weight for LRT: always selected
    featureSum = 6 / (1 + useFeatureSpecFlat + useFeatureSpecDiff);
    inst->weightLogLrt = featureSum;
    inst->weightSpecFlat = useFeatureSpecFlat * featureSum;
    inst->weightSpecDiff = useFeatureSpecDiff * featureSum;

    // set histograms to zero for next update
    WebRtcSpl_ZerosArrayW16(inst->histLrt, HIST_PAR_EST);
    WebRtcSpl_ZerosArrayW16(inst->histSpecDiff, HIST_PAR_EST);
    WebRtcSpl_ZerosArrayW16(inst->histSpecFlat, HIST_PAR_EST);
  } // end of flag == 1
}


// Compute spectral flatness on input spectrum
// magn is the magnitude spectrum
// spectral flatness is returned in inst->featureSpecFlat
void WebRtcNsx_ComputeSpectralFlatness(NsxInst_t* inst, WebRtc_UWord16* magn) {
  WebRtc_UWord32 tmpU32;
  WebRtc_UWord32 avgSpectralFlatnessNum, avgSpectralFlatnessDen;

  WebRtc_Word32 tmp32;
  WebRtc_Word32 currentSpectralFlatness, logCurSpectralFlatness;

  WebRtc_Word16 zeros, frac, intPart;

  int i;

  // for flatness
  avgSpectralFlatnessNum = 0;
  avgSpectralFlatnessDen = inst->sumMagn - (WebRtc_UWord32)magn[0]; // Q(normData-stages)

  // compute log of ratio of the geometric to arithmetic mean: check for log(0) case
  // flatness = exp( sum(log(magn[i]))/N - log(sum(magn[i])/N) )
  //          = exp( sum(log(magn[i]))/N ) * N / sum(magn[i])
  //          = 2^( sum(log2(magn[i]))/N - (log2(sum(magn[i])) - log2(N)) ) [This is used]
  for (i = 1; i < inst->magnLen; i++) {
    // First bin is excluded from spectrum measures. Number of bins is now a power of 2
    if (magn[i]) {
      zeros = WebRtcSpl_NormU32((WebRtc_UWord32)magn[i]);
      frac = (WebRtc_Word16)(((WebRtc_UWord32)((WebRtc_UWord32)(magn[i]) << zeros)
                              & 0x7FFFFFFF) >> 23);
      // log2(magn(i))
      assert(frac < 256);
      tmpU32 = (WebRtc_UWord32)(((31 - zeros) << 8)
                                + WebRtcNsx_kLogTableFrac[frac]); // Q8
      avgSpectralFlatnessNum += tmpU32; // Q8
    } else {
      //if at least one frequency component is zero, treat separately
      tmpU32 = WEBRTC_SPL_UMUL_32_16(inst->featureSpecFlat, SPECT_FLAT_TAVG_Q14); // Q24
      inst->featureSpecFlat -= WEBRTC_SPL_RSHIFT_U32(tmpU32, 14); // Q10
      return;
    }
  }
  //ratio and inverse log: check for case of log(0)
  zeros = WebRtcSpl_NormU32(avgSpectralFlatnessDen);
  frac = (WebRtc_Word16)(((avgSpectralFlatnessDen << zeros) & 0x7FFFFFFF) >> 23);
  // log2(avgSpectralFlatnessDen)
  assert(frac < 256);
  tmp32 = (WebRtc_Word32)(((31 - zeros) << 8) + WebRtcNsx_kLogTableFrac[frac]); // Q8
  logCurSpectralFlatness = (WebRtc_Word32)avgSpectralFlatnessNum;
  logCurSpectralFlatness += ((WebRtc_Word32)(inst->stages - 1) << (inst->stages + 7)); // Q(8+stages-1)
  logCurSpectralFlatness -= (tmp32 << (inst->stages - 1));
  logCurSpectralFlatness = WEBRTC_SPL_LSHIFT_W32(logCurSpectralFlatness, 10 - inst->stages); // Q17
  tmp32 = (WebRtc_Word32)(0x00020000 | (WEBRTC_SPL_ABS_W32(logCurSpectralFlatness)
                                        & 0x0001FFFF)); //Q17
  intPart = -(WebRtc_Word16)WEBRTC_SPL_RSHIFT_W32(logCurSpectralFlatness, 17);
  intPart += 7; // Shift 7 to get the output in Q10 (from Q17 = -17+10)
  if (intPart > 0) {
    currentSpectralFlatness = WEBRTC_SPL_RSHIFT_W32(tmp32, intPart);
  } else {
    currentSpectralFlatness = WEBRTC_SPL_LSHIFT_W32(tmp32, -intPart);
  }

  //time average update of spectral flatness feature
  tmp32 = currentSpectralFlatness - (WebRtc_Word32)inst->featureSpecFlat; // Q10
  tmp32 = WEBRTC_SPL_MUL_32_16(SPECT_FLAT_TAVG_Q14, tmp32); // Q24
  inst->featureSpecFlat = (WebRtc_UWord32)((WebRtc_Word32)inst->featureSpecFlat
                                           + WEBRTC_SPL_RSHIFT_W32(tmp32, 14)); // Q10
  // done with flatness feature
}


// Compute the difference measure between input spectrum and a template/learned noise spectrum
// magn_tmp is the input spectrum
// the reference/template spectrum is  inst->magn_avg_pause[i]
// returns (normalized) spectral difference in inst->featureSpecDiff
void WebRtcNsx_ComputeSpectralDifference(NsxInst_t* inst, WebRtc_UWord16* magnIn) {
  // This is to be calculated:
  // avgDiffNormMagn = var(magnIn) - cov(magnIn, magnAvgPause)^2 / var(magnAvgPause)

  WebRtc_UWord32 tmpU32no1, tmpU32no2;
  WebRtc_UWord32 varMagnUFX, varPauseUFX, avgDiffNormMagnUFX;

  WebRtc_Word32 tmp32no1, tmp32no2;
  WebRtc_Word32 avgPauseFX, avgMagnFX, covMagnPauseFX;
  WebRtc_Word32 maxPause, minPause;

  WebRtc_Word16 tmp16no1;

  int i, norm32, nShifts;

  avgPauseFX = 0;
  maxPause = 0;
  minPause = inst->avgMagnPause[0]; // Q(prevQMagn)
  // compute average quantities
  for (i = 0; i < inst->magnLen; i++) {
    // Compute mean of magn_pause
    avgPauseFX += inst->avgMagnPause[i]; // in Q(prevQMagn)
    maxPause = WEBRTC_SPL_MAX(maxPause, inst->avgMagnPause[i]);
    minPause = WEBRTC_SPL_MIN(minPause, inst->avgMagnPause[i]);
  }
  // normalize by replacing div of "inst->magnLen" with "inst->stages-1" shifts
  avgPauseFX = WEBRTC_SPL_RSHIFT_W32(avgPauseFX, inst->stages - 1);
  avgMagnFX = (WebRtc_Word32)WEBRTC_SPL_RSHIFT_U32(inst->sumMagn, inst->stages - 1);
  // Largest possible deviation in magnPause for (co)var calculations
  tmp32no1 = WEBRTC_SPL_MAX(maxPause - avgPauseFX, avgPauseFX - minPause);
  // Get number of shifts to make sure we don't get wrap around in varPause
  nShifts = WEBRTC_SPL_MAX(0, 10 + inst->stages - WebRtcSpl_NormW32(tmp32no1));

  varMagnUFX = 0;
  varPauseUFX = 0;
  covMagnPauseFX = 0;
  for (i = 0; i < inst->magnLen; i++) {
    // Compute var and cov of magn and magn_pause
    tmp16no1 = (WebRtc_Word16)((WebRtc_Word32)magnIn[i] - avgMagnFX);
    tmp32no2 = inst->avgMagnPause[i] - avgPauseFX;
    varMagnUFX += (WebRtc_UWord32)WEBRTC_SPL_MUL_16_16(tmp16no1, tmp16no1); // Q(2*qMagn)
    tmp32no1 = WEBRTC_SPL_MUL_32_16(tmp32no2, tmp16no1); // Q(prevQMagn+qMagn)
    covMagnPauseFX += tmp32no1; // Q(prevQMagn+qMagn)
    tmp32no1 = WEBRTC_SPL_RSHIFT_W32(tmp32no2, nShifts); // Q(prevQMagn-minPause)
    varPauseUFX += (WebRtc_UWord32)WEBRTC_SPL_MUL(tmp32no1, tmp32no1); // Q(2*(prevQMagn-minPause))
  }
  //update of average magnitude spectrum: Q(-2*stages) and averaging replaced by shifts
  inst->curAvgMagnEnergy += WEBRTC_SPL_RSHIFT_U32(inst->magnEnergy, 2 * inst->normData
                                                  + inst->stages - 1);

  avgDiffNormMagnUFX = varMagnUFX; // Q(2*qMagn)
  if ((varPauseUFX) && (covMagnPauseFX)) {
    tmpU32no1 = (WebRtc_UWord32)WEBRTC_SPL_ABS_W32(covMagnPauseFX); // Q(prevQMagn+qMagn)
    norm32 = WebRtcSpl_NormU32(tmpU32no1) - 16;
    if (norm32 > 0) {
      tmpU32no1 = WEBRTC_SPL_LSHIFT_U32(tmpU32no1, norm32); // Q(prevQMagn+qMagn+norm32)
    } else {
      tmpU32no1 = WEBRTC_SPL_RSHIFT_U32(tmpU32no1, -norm32); // Q(prevQMagn+qMagn+norm32)
    }
    tmpU32no2 = WEBRTC_SPL_UMUL(tmpU32no1, tmpU32no1); // Q(2*(prevQMagn+qMagn-norm32))

    nShifts += norm32;
    nShifts <<= 1;
    if (nShifts < 0) {
      varPauseUFX >>= (-nShifts); // Q(2*(qMagn+norm32+minPause))
      nShifts = 0;
    }
    if (varPauseUFX > 0) {
      // Q(2*(qMagn+norm32-16+minPause))
      tmpU32no1 = WEBRTC_SPL_UDIV(tmpU32no2, varPauseUFX);
      tmpU32no1 = WEBRTC_SPL_RSHIFT_U32(tmpU32no1, nShifts);

      // Q(2*qMagn)
      avgDiffNormMagnUFX -= WEBRTC_SPL_MIN(avgDiffNormMagnUFX, tmpU32no1);
    } else {
      avgDiffNormMagnUFX = 0;
    }
  }
  //normalize and compute time average update of difference feature
  tmpU32no1 = WEBRTC_SPL_RSHIFT_U32(avgDiffNormMagnUFX, 2 * inst->normData);
  if (inst->featureSpecDiff > tmpU32no1) {
    tmpU32no2 = WEBRTC_SPL_UMUL_32_16(inst->featureSpecDiff - tmpU32no1,
                                      SPECT_DIFF_TAVG_Q8); // Q(8-2*stages)
    inst->featureSpecDiff -= WEBRTC_SPL_RSHIFT_U32(tmpU32no2, 8); // Q(-2*stages)
  } else {
    tmpU32no2 = WEBRTC_SPL_UMUL_32_16(tmpU32no1 - inst->featureSpecDiff,
                                      SPECT_DIFF_TAVG_Q8); // Q(8-2*stages)
    inst->featureSpecDiff += WEBRTC_SPL_RSHIFT_U32(tmpU32no2, 8); // Q(-2*stages)
  }
}

// Compute speech/noise probability
// speech/noise probability is returned in: probSpeechFinal
//snrLocPrior is the prior SNR for each frequency (in Q11)
//snrLocPost is the post SNR for each frequency (in Q11)
void WebRtcNsx_SpeechNoiseProb(NsxInst_t* inst, WebRtc_UWord16* nonSpeechProbFinal,
                               WebRtc_UWord32* priorLocSnr, WebRtc_UWord32* postLocSnr) {
  WebRtc_UWord32 zeros, num, den, tmpU32no1, tmpU32no2, tmpU32no3;

  WebRtc_Word32 invLrtFX, indPriorFX, tmp32, tmp32no1, tmp32no2, besselTmpFX32;
  WebRtc_Word32 frac32, logTmp;
  WebRtc_Word32 logLrtTimeAvgKsumFX;

  WebRtc_Word16 indPriorFX16;
  WebRtc_Word16 tmp16, tmp16no1, tmp16no2, tmpIndFX, tableIndex, frac, intPart;

  int i, normTmp, normTmp2, nShifts;

  // compute feature based on average LR factor
  // this is the average over all frequencies of the smooth log LRT
  logLrtTimeAvgKsumFX = 0;
  for (i = 0; i < inst->magnLen; i++) {
    besselTmpFX32 = (WebRtc_Word32)postLocSnr[i]; // Q11
    normTmp = WebRtcSpl_NormU32(postLocSnr[i]);
    num = WEBRTC_SPL_LSHIFT_U32(postLocSnr[i], normTmp); // Q(11+normTmp)
    if (normTmp > 10) {
      den = WEBRTC_SPL_LSHIFT_U32(priorLocSnr[i], normTmp - 11); // Q(normTmp)
    } else {
      den = WEBRTC_SPL_RSHIFT_U32(priorLocSnr[i], 11 - normTmp); // Q(normTmp)
    }
    if (den > 0) {
      besselTmpFX32 -= WEBRTC_SPL_UDIV(num, den); // Q11
    } else {
      besselTmpFX32 -= num; // Q11
    }

    // inst->logLrtTimeAvg[i] += LRT_TAVG * (besselTmp - log(snrLocPrior) - inst->logLrtTimeAvg[i]);
    // Here, LRT_TAVG = 0.5
    zeros = WebRtcSpl_NormU32(priorLocSnr[i]);
    frac32 = (WebRtc_Word32)(((priorLocSnr[i] << zeros) & 0x7FFFFFFF) >> 19);
    tmp32 = WEBRTC_SPL_MUL(frac32, frac32);
    tmp32 = WEBRTC_SPL_RSHIFT_W32(WEBRTC_SPL_MUL(tmp32, -43), 19);
    tmp32 += WEBRTC_SPL_MUL_16_16_RSFT((WebRtc_Word16)frac32, 5412, 12);
    frac32 = tmp32 + 37;
    // tmp32 = log2(priorLocSnr[i])
    tmp32 = (WebRtc_Word32)(((31 - zeros) << 12) + frac32) - (11 << 12); // Q12
    logTmp = WEBRTC_SPL_RSHIFT_W32(WEBRTC_SPL_MUL_32_16(tmp32, 178), 8); // log2(priorLocSnr[i])*log(2)
    tmp32no1 = WEBRTC_SPL_RSHIFT_W32(logTmp + inst->logLrtTimeAvgW32[i], 1); // Q12
    inst->logLrtTimeAvgW32[i] += (besselTmpFX32 - tmp32no1); // Q12

    logLrtTimeAvgKsumFX += inst->logLrtTimeAvgW32[i]; // Q12
  }
  inst->featureLogLrt = WEBRTC_SPL_RSHIFT_W32(logLrtTimeAvgKsumFX * 5, inst->stages + 10); // 5 = BIN_SIZE_LRT / 2
  // done with computation of LR factor

  //
  //compute the indicator functions
  //

  // average LRT feature
  // FLOAT code
  // indicator0 = 0.5 * (tanh(widthPrior * (logLrtTimeAvgKsum - threshPrior0)) + 1.0);
  tmpIndFX = 16384; // Q14(1.0)
  tmp32no1 = logLrtTimeAvgKsumFX - inst->thresholdLogLrt; // Q12
  nShifts = 7 - inst->stages; // WIDTH_PR_MAP_SHIFT - inst->stages + 5;
  //use larger width in tanh map for pause regions
  if (tmp32no1 < 0) {
    tmpIndFX = 0;
    tmp32no1 = -tmp32no1;
    //widthPrior = widthPrior * 2.0;
    nShifts++;
  }
  tmp32no1 = WEBRTC_SPL_SHIFT_W32(tmp32no1, nShifts); // Q14
  // compute indicator function: sigmoid map
  tableIndex = (WebRtc_Word16)WEBRTC_SPL_RSHIFT_W32(tmp32no1, 14);
  if ((tableIndex < 16) && (tableIndex >= 0)) {
    tmp16no2 = kIndicatorTable[tableIndex];
    tmp16no1 = kIndicatorTable[tableIndex + 1] - kIndicatorTable[tableIndex];
    frac = (WebRtc_Word16)(tmp32no1 & 0x00003fff); // Q14
    tmp16no2 += (WebRtc_Word16)WEBRTC_SPL_MUL_16_16_RSFT(tmp16no1, frac, 14);
    if (tmpIndFX == 0) {
      tmpIndFX = 8192 - tmp16no2; // Q14
    } else {
      tmpIndFX = 8192 + tmp16no2; // Q14
    }
  }
  indPriorFX = WEBRTC_SPL_MUL_16_16(inst->weightLogLrt, tmpIndFX); // 6*Q14

  //spectral flatness feature
  if (inst->weightSpecFlat) {
    tmpU32no1 = WEBRTC_SPL_UMUL(inst->featureSpecFlat, 400); // Q10
    tmpIndFX = 16384; // Q14(1.0)
    //use larger width in tanh map for pause regions
    tmpU32no2 = inst->thresholdSpecFlat - tmpU32no1; //Q10
    nShifts = 4;
    if (inst->thresholdSpecFlat < tmpU32no1) {
      tmpIndFX = 0;
      tmpU32no2 = tmpU32no1 - inst->thresholdSpecFlat;
      //widthPrior = widthPrior * 2.0;
      nShifts++;
    }
    tmp32no1 = (WebRtc_Word32)WebRtcSpl_DivU32U16(WEBRTC_SPL_LSHIFT_U32(tmpU32no2,
                                                                        nShifts), 25); //Q14
    tmpU32no1 = WebRtcSpl_DivU32U16(WEBRTC_SPL_LSHIFT_U32(tmpU32no2, nShifts), 25); //Q14
    // compute indicator function: sigmoid map
    // FLOAT code
    // indicator1 = 0.5 * (tanh(sgnMap * widthPrior * (threshPrior1 - tmpFloat1)) + 1.0);
    tableIndex = (WebRtc_Word16)WEBRTC_SPL_RSHIFT_U32(tmpU32no1, 14);
    if (tableIndex < 16) {
      tmp16no2 = kIndicatorTable[tableIndex];
      tmp16no1 = kIndicatorTable[tableIndex + 1] - kIndicatorTable[tableIndex];
      frac = (WebRtc_Word16)(tmpU32no1 & 0x00003fff); // Q14
      tmp16no2 += (WebRtc_Word16)WEBRTC_SPL_MUL_16_16_RSFT(tmp16no1, frac, 14);
      if (tmpIndFX) {
        tmpIndFX = 8192 + tmp16no2; // Q14
      } else {
        tmpIndFX = 8192 - tmp16no2; // Q14
      }
    }
    indPriorFX += WEBRTC_SPL_MUL_16_16(inst->weightSpecFlat, tmpIndFX); // 6*Q14
  }

  //for template spectral-difference
  if (inst->weightSpecDiff) {
    tmpU32no1 = 0;
    if (inst->featureSpecDiff) {
      normTmp = WEBRTC_SPL_MIN(20 - inst->stages,
                               WebRtcSpl_NormU32(inst->featureSpecDiff));
      tmpU32no1 = WEBRTC_SPL_LSHIFT_U32(inst->featureSpecDiff, normTmp); // Q(normTmp-2*stages)
      tmpU32no2 = WEBRTC_SPL_RSHIFT_U32(inst->timeAvgMagnEnergy, 20 - inst->stages
                                        - normTmp);
      if (tmpU32no2 > 0) {
        // Q(20 - inst->stages)
        tmpU32no1 = WEBRTC_SPL_UDIV(tmpU32no1, tmpU32no2);
      } else {
        tmpU32no1 = (WebRtc_UWord32)(0x7fffffff);
      }
    }
    tmpU32no3 = WEBRTC_SPL_UDIV(WEBRTC_SPL_LSHIFT_U32(inst->thresholdSpecDiff, 17), 25);
    tmpU32no2 = tmpU32no1 - tmpU32no3;
    nShifts = 1;
    tmpIndFX = 16384; // Q14(1.0)
    //use larger width in tanh map for pause regions
    if (tmpU32no2 & 0x80000000) {
      tmpIndFX = 0;
      tmpU32no2 = tmpU32no3 - tmpU32no1;
      //widthPrior = widthPrior * 2.0;
      nShifts--;
    }
    tmpU32no1 = WEBRTC_SPL_RSHIFT_U32(tmpU32no2, nShifts);
    // compute indicator function: sigmoid map
    /* FLOAT code
     indicator2 = 0.5 * (tanh(widthPrior * (tmpFloat1 - threshPrior2)) + 1.0);
     */
    tableIndex = (WebRtc_Word16)WEBRTC_SPL_RSHIFT_U32(tmpU32no1, 14);
    if (tableIndex < 16) {
      tmp16no2 = kIndicatorTable[tableIndex];
      tmp16no1 = kIndicatorTable[tableIndex + 1] - kIndicatorTable[tableIndex];
      frac = (WebRtc_Word16)(tmpU32no1 & 0x00003fff); // Q14
      tmp16no2 += (WebRtc_Word16)WEBRTC_SPL_MUL_16_16_RSFT_WITH_ROUND(
                    tmp16no1, frac, 14);
      if (tmpIndFX) {
        tmpIndFX = 8192 + tmp16no2;
      } else {
        tmpIndFX = 8192 - tmp16no2;
      }
    }
    indPriorFX += WEBRTC_SPL_MUL_16_16(inst->weightSpecDiff, tmpIndFX); // 6*Q14
  }

  //combine the indicator function with the feature weights
  // FLOAT code
  // indPrior = 1 - (weightIndPrior0 * indicator0 + weightIndPrior1 * indicator1 + weightIndPrior2 * indicator2);
  indPriorFX16 = WebRtcSpl_DivW32W16ResW16(98307 - indPriorFX, 6); // Q14
  // done with computing indicator function

  //compute the prior probability
  // FLOAT code
  // inst->priorNonSpeechProb += PRIOR_UPDATE * (indPriorNonSpeech - inst->priorNonSpeechProb);
  tmp16 = indPriorFX16 - inst->priorNonSpeechProb; // Q14
  inst->priorNonSpeechProb += (WebRtc_Word16)WEBRTC_SPL_MUL_16_16_RSFT(
                                PRIOR_UPDATE_Q14, tmp16, 14); // Q14

  //final speech probability: combine prior model with LR factor:

  memset(nonSpeechProbFinal, 0, sizeof(WebRtc_UWord16) * inst->magnLen);

  if (inst->priorNonSpeechProb > 0) {
    for (i = 0; i < inst->magnLen; i++) {
      // FLOAT code
      // invLrt = exp(inst->logLrtTimeAvg[i]);
      // invLrt = inst->priorSpeechProb * invLrt;
      // nonSpeechProbFinal[i] = (1.0 - inst->priorSpeechProb) / (1.0 - inst->priorSpeechProb + invLrt);
      // invLrt = (1.0 - inst->priorNonSpeechProb) * invLrt;
      // nonSpeechProbFinal[i] = inst->priorNonSpeechProb / (inst->priorNonSpeechProb + invLrt);
      if (inst->logLrtTimeAvgW32[i] < 65300) {
        tmp32no1 = WEBRTC_SPL_RSHIFT_W32(WEBRTC_SPL_MUL(inst->logLrtTimeAvgW32[i], 23637),
                                         14); // Q12
        intPart = (WebRtc_Word16)WEBRTC_SPL_RSHIFT_W32(tmp32no1, 12);
        if (intPart < -8) {
          intPart = -8;
        }
        frac = (WebRtc_Word16)(tmp32no1 & 0x00000fff); // Q12

        // Quadratic approximation of 2^frac
        tmp32no2 = WEBRTC_SPL_RSHIFT_W32(frac * frac * 44, 19); // Q12
        tmp32no2 += WEBRTC_SPL_MUL_16_16_RSFT(frac, 84, 7); // Q12
        invLrtFX = WEBRTC_SPL_LSHIFT_W32(1, 8 + intPart)
                   + WEBRTC_SPL_SHIFT_W32(tmp32no2, intPart - 4); // Q8

        normTmp = WebRtcSpl_NormW32(invLrtFX);
        normTmp2 = WebRtcSpl_NormW16((16384 - inst->priorNonSpeechProb));
        if (normTmp + normTmp2 >= 7) {
          if (normTmp + normTmp2 < 15) {
            invLrtFX = WEBRTC_SPL_RSHIFT_W32(invLrtFX, 15 - normTmp2 - normTmp);
            // Q(normTmp+normTmp2-7)
            tmp32no1 = WEBRTC_SPL_MUL_32_16(invLrtFX, (16384 - inst->priorNonSpeechProb));
            // Q(normTmp+normTmp2+7)
            invLrtFX = WEBRTC_SPL_SHIFT_W32(tmp32no1, 7 - normTmp - normTmp2); // Q14
          } else {
            tmp32no1 = WEBRTC_SPL_MUL_32_16(invLrtFX, (16384 - inst->priorNonSpeechProb)); // Q22
            invLrtFX = WEBRTC_SPL_RSHIFT_W32(tmp32no1, 8); // Q14
          }

          tmp32no1 = WEBRTC_SPL_LSHIFT_W32((WebRtc_Word32)inst->priorNonSpeechProb, 8); // Q22

          nonSpeechProbFinal[i] = (WebRtc_UWord16)WEBRTC_SPL_DIV(tmp32no1,
              (WebRtc_Word32)inst->priorNonSpeechProb + invLrtFX); // Q8
        }
      }
    }
  }
}

// Transform input (speechFrame) to frequency domain magnitude (magnU16)
void WebRtcNsx_DataAnalysis(NsxInst_t* inst, short* speechFrame, WebRtc_UWord16* magnU16) {

  WebRtc_UWord32 tmpU32no1, tmpU32no2;

  WebRtc_Word32   tmp_1_w32 = 0;
  WebRtc_Word32   tmp_2_w32 = 0;
  WebRtc_Word32   sum_log_magn = 0;
  WebRtc_Word32   sum_log_i_log_magn = 0;

  WebRtc_UWord16  sum_log_magn_u16 = 0;
  WebRtc_UWord16  tmp_u16 = 0;

  WebRtc_Word16   sum_log_i = 0;
  WebRtc_Word16   sum_log_i_square = 0;
  WebRtc_Word16   frac = 0;
  WebRtc_Word16   log2 = 0;
  WebRtc_Word16   matrix_determinant = 0;
  WebRtc_Word16   winData[ANAL_BLOCKL_MAX], maxWinData;
  WebRtc_Word16   realImag[ANAL_BLOCKL_MAX << 1];

  int i, j;
  int zeros;
  int net_norm = 0;
  int right_shifts_in_magnU16 = 0;
  int right_shifts_in_initMagnEst = 0;

  // Update analysis buffer for lower band, and window data before FFT.
  WebRtcNsx_AnalysisUpdate(inst, winData, speechFrame);

  // Get input energy
  inst->energyIn = WebRtcSpl_Energy(winData, (int)inst->anaLen, &(inst->scaleEnergyIn));

  // Reset zero input flag
  inst->zeroInputSignal = 0;
  // Acquire norm for winData
  maxWinData = WebRtcSpl_MaxAbsValueW16(winData, inst->anaLen);
  inst->normData = WebRtcSpl_NormW16(maxWinData);
  if (maxWinData == 0) {
    // Treat zero input separately.
    inst->zeroInputSignal = 1;
    return;
  }

  // Determine the net normalization in the frequency domain
  net_norm = inst->stages - inst->normData;
  // Track lowest normalization factor and use it to prevent wrap around in shifting
  right_shifts_in_magnU16 = inst->normData - inst->minNorm;
  right_shifts_in_initMagnEst = WEBRTC_SPL_MAX(-right_shifts_in_magnU16, 0);
  inst->minNorm -= right_shifts_in_initMagnEst;
  right_shifts_in_magnU16 = WEBRTC_SPL_MAX(right_shifts_in_magnU16, 0);

  // create realImag as winData interleaved with zeros (= imag. part), normalize it
  WebRtcNsx_CreateComplexBuffer(inst, winData, realImag);

  // bit-reverse position of elements in array and FFT the array
  WebRtcSpl_ComplexBitReverse(realImag, inst->stages); // Q(normData-stages)
  WebRtcSpl_ComplexFFT(realImag, inst->stages, 1);

  inst->imag[0] = 0; // Q(normData-stages)
  inst->imag[inst->anaLen2] = 0;
  inst->real[0] = realImag[0]; // Q(normData-stages)
  inst->real[inst->anaLen2] = realImag[inst->anaLen];
  // Q(2*(normData-stages))
  inst->magnEnergy = (WebRtc_UWord32)WEBRTC_SPL_MUL_16_16(inst->real[0], inst->real[0]);
  inst->magnEnergy += (WebRtc_UWord32)WEBRTC_SPL_MUL_16_16(inst->real[inst->anaLen2],
                                                           inst->real[inst->anaLen2]);
  magnU16[0] = (WebRtc_UWord16)WEBRTC_SPL_ABS_W16(inst->real[0]); // Q(normData-stages)
  magnU16[inst->anaLen2] = (WebRtc_UWord16)WEBRTC_SPL_ABS_W16(inst->real[inst->anaLen2]);
  inst->sumMagn = (WebRtc_UWord32)magnU16[0]; // Q(normData-stages)
  inst->sumMagn += (WebRtc_UWord32)magnU16[inst->anaLen2];

  if (inst->blockIndex >= END_STARTUP_SHORT) {
    for (i = 1, j = 2; i < inst->anaLen2; i += 1, j += 2) {
      inst->real[i] = realImag[j];
      inst->imag[i] = -realImag[j + 1];
      // magnitude spectrum
      // energy in Q(2*(normData-stages))
      tmpU32no1 = (WebRtc_UWord32)WEBRTC_SPL_MUL_16_16(realImag[j], realImag[j]);
      tmpU32no1 += (WebRtc_UWord32)WEBRTC_SPL_MUL_16_16(realImag[j + 1], realImag[j + 1]);
      inst->magnEnergy += tmpU32no1; // Q(2*(normData-stages))

      magnU16[i] = (WebRtc_UWord16)WebRtcSpl_SqrtFloor(tmpU32no1); // Q(normData-stages)
      inst->sumMagn += (WebRtc_UWord32)magnU16[i]; // Q(normData-stages)
    }
  } else {
    //
    // Gather information during startup for noise parameter estimation
    //

    // Switch initMagnEst to Q(minNorm-stages)
    inst->initMagnEst[0] = WEBRTC_SPL_RSHIFT_U32(inst->initMagnEst[0],
                                                 right_shifts_in_initMagnEst);
    inst->initMagnEst[inst->anaLen2] =
      WEBRTC_SPL_RSHIFT_U32(inst->initMagnEst[inst->anaLen2],
                            right_shifts_in_initMagnEst); // Q(minNorm-stages)

    // Shift magnU16 to same domain as initMagnEst
    tmpU32no1 = WEBRTC_SPL_RSHIFT_W32((WebRtc_UWord32)magnU16[0],
                                      right_shifts_in_magnU16); // Q(minNorm-stages)
    tmpU32no2 = WEBRTC_SPL_RSHIFT_W32((WebRtc_UWord32)magnU16[inst->anaLen2],
                                      right_shifts_in_magnU16); // Q(minNorm-stages)

    // Update initMagnEst
    inst->initMagnEst[0] += tmpU32no1; // Q(minNorm-stages)
    inst->initMagnEst[inst->anaLen2] += tmpU32no2; // Q(minNorm-stages)

    log2 = 0;
    if (magnU16[inst->anaLen2]) {
      // Calculate log2(magnU16[inst->anaLen2])
      zeros = WebRtcSpl_NormU32((WebRtc_UWord32)magnU16[inst->anaLen2]);
      frac = (WebRtc_Word16)((((WebRtc_UWord32)magnU16[inst->anaLen2] << zeros) &
                              0x7FFFFFFF) >> 23); // Q8
      // log2(magnU16(i)) in Q8
      assert(frac < 256);
      log2 = (WebRtc_Word16)(((31 - zeros) << 8) + WebRtcNsx_kLogTableFrac[frac]);
    }

    sum_log_magn = (WebRtc_Word32)log2; // Q8
    // sum_log_i_log_magn in Q17
    sum_log_i_log_magn = (WEBRTC_SPL_MUL_16_16(kLogIndex[inst->anaLen2], log2) >> 3);

    for (i = 1, j = 2; i < inst->anaLen2; i += 1, j += 2) {
      inst->real[i] = realImag[j];
      inst->imag[i] = -realImag[j + 1];
      // magnitude spectrum
      // energy in Q(2*(normData-stages))
      tmpU32no1 = (WebRtc_UWord32)WEBRTC_SPL_MUL_16_16(realImag[j], realImag[j]);
      tmpU32no1 += (WebRtc_UWord32)WEBRTC_SPL_MUL_16_16(realImag[j + 1], realImag[j + 1]);
      inst->magnEnergy += tmpU32no1; // Q(2*(normData-stages))

      magnU16[i] = (WebRtc_UWord16)WebRtcSpl_SqrtFloor(tmpU32no1); // Q(normData-stages)
      inst->sumMagn += (WebRtc_UWord32)magnU16[i]; // Q(normData-stages)

      // Switch initMagnEst to Q(minNorm-stages)
      inst->initMagnEst[i] = WEBRTC_SPL_RSHIFT_U32(inst->initMagnEst[i],
                                                   right_shifts_in_initMagnEst);

      // Shift magnU16 to same domain as initMagnEst, i.e., Q(minNorm-stages)
      tmpU32no1 = WEBRTC_SPL_RSHIFT_W32((WebRtc_UWord32)magnU16[i],
                                        right_shifts_in_magnU16);
      // Update initMagnEst
      inst->initMagnEst[i] += tmpU32no1; // Q(minNorm-stages)

      if (i >= kStartBand) {
        // For pink noise estimation. Collect data neglecting lower frequency band
        log2 = 0;
        if (magnU16[i]) {
          zeros = WebRtcSpl_NormU32((WebRtc_UWord32)magnU16[i]);
          frac = (WebRtc_Word16)((((WebRtc_UWord32)magnU16[i] << zeros) &
                                  0x7FFFFFFF) >> 23);
          // log2(magnU16(i)) in Q8
          assert(frac < 256);
          log2 = (WebRtc_Word16)(((31 - zeros) << 8)
                                 + WebRtcNsx_kLogTableFrac[frac]);
        }
        sum_log_magn += (WebRtc_Word32)log2; // Q8
        // sum_log_i_log_magn in Q17
        sum_log_i_log_magn += (WEBRTC_SPL_MUL_16_16(kLogIndex[i], log2) >> 3);
      }
    }

    //
    //compute simplified noise model during startup
    //

    // Estimate White noise

    // Switch whiteNoiseLevel to Q(minNorm-stages)
    inst->whiteNoiseLevel = WEBRTC_SPL_RSHIFT_U32(inst->whiteNoiseLevel,
                                                  right_shifts_in_initMagnEst);

    // Update the average magnitude spectrum, used as noise estimate.
    tmpU32no1 = WEBRTC_SPL_UMUL_32_16(inst->sumMagn, inst->overdrive);
    tmpU32no1 = WEBRTC_SPL_RSHIFT_U32(tmpU32no1, inst->stages + 8);

    // Replacing division above with 'stages' shifts
    // Shift to same Q-domain as whiteNoiseLevel
    tmpU32no1 = WEBRTC_SPL_RSHIFT_U32(tmpU32no1, right_shifts_in_magnU16);
    // This operation is safe from wrap around as long as END_STARTUP_SHORT < 128
    assert(END_STARTUP_SHORT < 128);
    inst->whiteNoiseLevel += tmpU32no1; // Q(minNorm-stages)

    // Estimate Pink noise parameters
    // Denominator used in both parameter estimates.
    // The value is only dependent on the size of the frequency band (kStartBand)
    // and to reduce computational complexity stored in a table (kDeterminantEstMatrix[])
    assert(kStartBand < 66);
    matrix_determinant = kDeterminantEstMatrix[kStartBand]; // Q0
    sum_log_i = kSumLogIndex[kStartBand]; // Q5
    sum_log_i_square = kSumSquareLogIndex[kStartBand]; // Q2
    if (inst->fs == 8000) {
      // Adjust values to shorter blocks in narrow band.
      tmp_1_w32 = (WebRtc_Word32)matrix_determinant;
      tmp_1_w32 += WEBRTC_SPL_MUL_16_16_RSFT(kSumLogIndex[65], sum_log_i, 9);
      tmp_1_w32 -= WEBRTC_SPL_MUL_16_16_RSFT(kSumLogIndex[65], kSumLogIndex[65], 10);
      tmp_1_w32 -= WEBRTC_SPL_LSHIFT_W32((WebRtc_Word32)sum_log_i_square, 4);
      tmp_1_w32 -= WEBRTC_SPL_MUL_16_16_RSFT((WebRtc_Word16)
                       (inst->magnLen - kStartBand), kSumSquareLogIndex[65], 2);
      matrix_determinant = (WebRtc_Word16)tmp_1_w32;
      sum_log_i -= kSumLogIndex[65]; // Q5
      sum_log_i_square -= kSumSquareLogIndex[65]; // Q2
    }

    // Necessary number of shifts to fit sum_log_magn in a word16
    zeros = 16 - WebRtcSpl_NormW32(sum_log_magn);
    if (zeros < 0) {
      zeros = 0;
    }
    tmp_1_w32 = WEBRTC_SPL_LSHIFT_W32(sum_log_magn, 1); // Q9
    sum_log_magn_u16 = (WebRtc_UWord16)WEBRTC_SPL_RSHIFT_W32(tmp_1_w32, zeros);//Q(9-zeros)

    // Calculate and update pinkNoiseNumerator. Result in Q11.
    tmp_2_w32 = WEBRTC_SPL_MUL_16_U16(sum_log_i_square, sum_log_magn_u16); // Q(11-zeros)
    tmpU32no1 = WEBRTC_SPL_RSHIFT_U32((WebRtc_UWord32)sum_log_i_log_magn, 12); // Q5

    // Shift the largest value of sum_log_i and tmp32no3 before multiplication
    tmp_u16 = WEBRTC_SPL_LSHIFT_U16((WebRtc_UWord16)sum_log_i, 1); // Q6
    if ((WebRtc_UWord32)sum_log_i > tmpU32no1) {
      tmp_u16 = WEBRTC_SPL_RSHIFT_U16(tmp_u16, zeros);
    } else {
      tmpU32no1 = WEBRTC_SPL_RSHIFT_U32(tmpU32no1, zeros);
    }
    tmp_2_w32 -= (WebRtc_Word32)WEBRTC_SPL_UMUL_32_16(tmpU32no1, tmp_u16); // Q(11-zeros)
    matrix_determinant = WEBRTC_SPL_RSHIFT_W16(matrix_determinant, zeros); // Q(-zeros)
    tmp_2_w32 = WebRtcSpl_DivW32W16(tmp_2_w32, matrix_determinant); // Q11
    tmp_2_w32 += WEBRTC_SPL_LSHIFT_W32((WebRtc_Word32)net_norm, 11); // Q11
    if (tmp_2_w32 < 0) {
      tmp_2_w32 = 0;
    }
    inst->pinkNoiseNumerator += tmp_2_w32; // Q11

    // Calculate and update pinkNoiseExp. Result in Q14.
    tmp_2_w32 = WEBRTC_SPL_MUL_16_U16(sum_log_i, sum_log_magn_u16); // Q(14-zeros)
    tmp_1_w32 = WEBRTC_SPL_RSHIFT_W32(sum_log_i_log_magn, 3 + zeros);
    tmp_1_w32 = WEBRTC_SPL_MUL((WebRtc_Word32)(inst->magnLen - kStartBand),
                               tmp_1_w32);
    tmp_2_w32 -= tmp_1_w32; // Q(14-zeros)
    if (tmp_2_w32 > 0) {
      // If the exponential parameter is negative force it to zero, which means a
      // flat spectrum.
      tmp_1_w32 = WebRtcSpl_DivW32W16(tmp_2_w32, matrix_determinant); // Q14
      inst->pinkNoiseExp += WEBRTC_SPL_SAT(16384, tmp_1_w32, 0); // Q14
    }
  }
}

void WebRtcNsx_DataSynthesis(NsxInst_t* inst, short* outFrame) {
  WebRtc_Word32 energyOut;

  WebRtc_Word16 realImag[ANAL_BLOCKL_MAX << 1];
  WebRtc_Word16 tmp16no1, tmp16no2;
  WebRtc_Word16 energyRatio;
  WebRtc_Word16 gainFactor, gainFactor1, gainFactor2;

  int i;
  int outCIFFT;
  int scaleEnergyOut = 0;

  if (inst->zeroInputSignal) {
    // synthesize the special case of zero input
    // read out fully processed segment
    for (i = 0; i < inst->blockLen10ms; i++) {
      outFrame[i] = inst->synthesisBuffer[i]; // Q0
    }
    // update synthesis buffer
    WEBRTC_SPL_MEMCPY_W16(inst->synthesisBuffer,
                          inst->synthesisBuffer + inst->blockLen10ms,
                          inst->anaLen - inst->blockLen10ms);
    WebRtcSpl_ZerosArrayW16(inst->synthesisBuffer + inst->anaLen - inst->blockLen10ms,
                            inst->blockLen10ms);
    return;
  }

  // Filter the data in the frequency domain, and create spectrum.
  WebRtcNsx_PrepareSpectrum(inst, realImag);

  // bit-reverse position of elements in array and IFFT it
  WebRtcSpl_ComplexBitReverse(realImag, inst->stages);
  outCIFFT = WebRtcSpl_ComplexIFFT(realImag, inst->stages, 1);

  // Denormalize.
  WebRtcNsx_Denormalize(inst, realImag, outCIFFT);

  //scale factor: only do it after END_STARTUP_LONG time
  gainFactor = 8192; // 8192 = Q13(1.0)
  if (inst->gainMap == 1 &&
      inst->blockIndex > END_STARTUP_LONG &&
      inst->energyIn > 0) {
    energyOut = WebRtcSpl_Energy(inst->real, (int)inst->anaLen, &scaleEnergyOut); // Q(-scaleEnergyOut)
    if (scaleEnergyOut == 0 && !(energyOut & 0x7f800000)) {
      energyOut = WEBRTC_SPL_SHIFT_W32(energyOut, 8 + scaleEnergyOut
                                       - inst->scaleEnergyIn);
    } else {
      inst->energyIn = WEBRTC_SPL_RSHIFT_W32(inst->energyIn, 8 + scaleEnergyOut
                                             - inst->scaleEnergyIn); // Q(-8-scaleEnergyOut)
    }

    assert(inst->energyIn > 0);
    energyRatio = (WebRtc_Word16)WEBRTC_SPL_DIV(energyOut
        + WEBRTC_SPL_RSHIFT_W32(inst->energyIn, 1), inst->energyIn); // Q8
    // Limit the ratio to [0, 1] in Q8, i.e., [0, 256]
    energyRatio = WEBRTC_SPL_SAT(256, energyRatio, 0);

    // all done in lookup tables now
    assert(energyRatio < 257);
    gainFactor1 = kFactor1Table[energyRatio]; // Q8
    gainFactor2 = inst->factor2Table[energyRatio]; // Q8

    //combine both scales with speech/noise prob: note prior (priorSpeechProb) is not frequency dependent

    // factor = inst->priorSpeechProb*factor1 + (1.0-inst->priorSpeechProb)*factor2; // original code
    tmp16no1 = (WebRtc_Word16)WEBRTC_SPL_MUL_16_16_RSFT(16384 - inst->priorNonSpeechProb,
                                                        gainFactor1, 14); // Q13 16384 = Q14(1.0)
    tmp16no2 = (WebRtc_Word16)WEBRTC_SPL_MUL_16_16_RSFT(inst->priorNonSpeechProb,
                                                        gainFactor2, 14); // Q13;
    gainFactor = tmp16no1 + tmp16no2; // Q13
  } // out of flag_gain_map==1

  // Synthesis, read out fully processed segment, and update synthesis buffer.
  WebRtcNsx_SynthesisUpdate(inst, outFrame, gainFactor);
}

int WebRtcNsx_ProcessCore(NsxInst_t* inst, short* speechFrame, short* speechFrameHB,
                          short* outFrame, short* outFrameHB) {
  // main routine for noise suppression

  WebRtc_UWord32 tmpU32no1, tmpU32no2, tmpU32no3;
  WebRtc_UWord32 satMax, maxNoiseU32;
  WebRtc_UWord32 tmpMagnU32, tmpNoiseU32;
  WebRtc_UWord32 nearMagnEst;
  WebRtc_UWord32 noiseUpdateU32;
  WebRtc_UWord32 noiseU32[HALF_ANAL_BLOCKL];
  WebRtc_UWord32 postLocSnr[HALF_ANAL_BLOCKL];
  WebRtc_UWord32 priorLocSnr[HALF_ANAL_BLOCKL];
  WebRtc_UWord32 prevNearSnr[HALF_ANAL_BLOCKL];
  WebRtc_UWord32 curNearSnr;
  WebRtc_UWord32 priorSnr;
  WebRtc_UWord32 noise_estimate = 0;
  WebRtc_UWord32 noise_estimate_avg = 0;
  WebRtc_UWord32 numerator = 0;

  WebRtc_Word32 tmp32no1, tmp32no2;
  WebRtc_Word32 pink_noise_num_avg = 0;

  WebRtc_UWord16 tmpU16no1;
  WebRtc_UWord16 magnU16[HALF_ANAL_BLOCKL];
  WebRtc_UWord16 prevNoiseU16[HALF_ANAL_BLOCKL];
  WebRtc_UWord16 nonSpeechProbFinal[HALF_ANAL_BLOCKL];
  WebRtc_UWord16 gammaNoise, prevGammaNoise;
  WebRtc_UWord16 noiseSupFilterTmp[HALF_ANAL_BLOCKL];

  WebRtc_Word16 qMagn, qNoise;
  WebRtc_Word16 avgProbSpeechHB, gainModHB, avgFilterGainHB, gainTimeDomainHB;
  WebRtc_Word16 pink_noise_exp_avg = 0;

  int i;
  int nShifts, postShifts;
  int norm32no1, norm32no2;
  int flag, sign;
  int q_domain_to_use = 0;

  // Code for ARMv7-Neon platform assumes the following:
  assert(inst->anaLen % 16 == 0);
  assert(inst->anaLen2 % 8 == 0);
  assert(inst->blockLen10ms % 16 == 0);
  assert(inst->magnLen == inst->anaLen2 + 1);

#ifdef NS_FILEDEBUG
  fwrite(spframe, sizeof(short), inst->blockLen10ms, inst->infile);
#endif

  // Check that initialization has been done
  if (inst->initFlag != 1) {
    return -1;
  }
  // Check for valid pointers based on sampling rate
  if ((inst->fs == 32000) && (speechFrameHB == NULL)) {
    return -1;
  }

  // Store speechFrame and transform to frequency domain
  WebRtcNsx_DataAnalysis(inst, speechFrame, magnU16);

  if (inst->zeroInputSignal) {
    WebRtcNsx_DataSynthesis(inst, outFrame);

    if (inst->fs == 32000) {
      // update analysis buffer for H band
      // append new data to buffer FX
      WEBRTC_SPL_MEMCPY_W16(inst->dataBufHBFX, inst->dataBufHBFX + inst->blockLen10ms,
                            inst->anaLen - inst->blockLen10ms);
      WEBRTC_SPL_MEMCPY_W16(inst->dataBufHBFX + inst->anaLen - inst->blockLen10ms,
                            speechFrameHB, inst->blockLen10ms);
      for (i = 0; i < inst->blockLen10ms; i++) {
        outFrameHB[i] = inst->dataBufHBFX[i]; // Q0
      }
    } // end of H band gain computation
    return 0;
  }

  // Update block index when we have something to process
  inst->blockIndex++;
  //

  // Norm of magn
  qMagn = inst->normData - inst->stages;

  // Compute spectral flatness on input spectrum
  WebRtcNsx_ComputeSpectralFlatness(inst, magnU16);

  // quantile noise estimate
  WebRtcNsx_NoiseEstimation(inst, magnU16, noiseU32, &qNoise);

  //noise estimate from previous frame
  for (i = 0; i < inst->magnLen; i++) {
    prevNoiseU16[i] = (WebRtc_UWord16)WEBRTC_SPL_RSHIFT_U32(inst->prevNoiseU32[i], 11); // Q(prevQNoise)
  }

  if (inst->blockIndex < END_STARTUP_SHORT) {
    // Noise Q-domain to be used later; see description at end of section.
    q_domain_to_use = WEBRTC_SPL_MIN((int)qNoise, inst->minNorm - inst->stages);

    // Calculate frequency independent parts in parametric noise estimate and calculate
    // the estimate for the lower frequency band (same values for all frequency bins)
    if (inst->pinkNoiseExp) {
      pink_noise_exp_avg = (WebRtc_Word16)WebRtcSpl_DivW32W16(inst->pinkNoiseExp,
                                                              (WebRtc_Word16)(inst->blockIndex + 1)); // Q14
      pink_noise_num_avg = WebRtcSpl_DivW32W16(inst->pinkNoiseNumerator,
                                               (WebRtc_Word16)(inst->blockIndex + 1)); // Q11
      WebRtcNsx_CalcParametricNoiseEstimate(inst,
                                            pink_noise_exp_avg,
                                            pink_noise_num_avg,
                                            kStartBand,
                                            &noise_estimate,
                                            &noise_estimate_avg);
    } else {
      // Use white noise estimate if we have poor pink noise parameter estimates
      noise_estimate = inst->whiteNoiseLevel; // Q(minNorm-stages)
      noise_estimate_avg = noise_estimate / (inst->blockIndex + 1); // Q(minNorm-stages)
    }
    for (i = 0; i < inst->magnLen; i++) {
      // Estimate the background noise using the pink noise parameters if permitted
      if ((inst->pinkNoiseExp) && (i >= kStartBand)) {
        // Reset noise_estimate
        noise_estimate = 0;
        noise_estimate_avg = 0;
        // Calculate the parametric noise estimate for current frequency bin
        WebRtcNsx_CalcParametricNoiseEstimate(inst,
                                              pink_noise_exp_avg,
                                              pink_noise_num_avg,
                                              i,
                                              &noise_estimate,
                                              &noise_estimate_avg);
      }
      // Calculate parametric Wiener filter
      noiseSupFilterTmp[i] = inst->denoiseBound;
      if (inst->initMagnEst[i]) {
        // numerator = (initMagnEst - noise_estimate * overdrive)
        // Result in Q(8+minNorm-stages)
        tmpU32no1 = WEBRTC_SPL_UMUL_32_16(noise_estimate, inst->overdrive);
        numerator = WEBRTC_SPL_LSHIFT_U32(inst->initMagnEst[i], 8);
        if (numerator > tmpU32no1) {
          // Suppression filter coefficient larger than zero, so calculate.
          numerator -= tmpU32no1;

          // Determine number of left shifts in numerator for best accuracy after
          // division
          nShifts = WebRtcSpl_NormU32(numerator);
          nShifts = WEBRTC_SPL_SAT(6, nShifts, 0);

          // Shift numerator to Q(nShifts+8+minNorm-stages)
          numerator = WEBRTC_SPL_LSHIFT_U32(numerator, nShifts);

          // Shift denominator to Q(nShifts-6+minNorm-stages)
          tmpU32no1 = WEBRTC_SPL_RSHIFT_U32(inst->initMagnEst[i], 6 - nShifts);
          if (tmpU32no1 == 0) {
            // This is only possible if numerator = 0, in which case
            // we don't need any division.
            tmpU32no1 = 1;
          }
          tmpU32no2 = WEBRTC_SPL_UDIV(numerator, tmpU32no1); // Q14
          noiseSupFilterTmp[i] = (WebRtc_UWord16)WEBRTC_SPL_SAT(16384, tmpU32no2,
              (WebRtc_UWord32)(inst->denoiseBound)); // Q14
        }
      }
      // Weight quantile noise 'noiseU32' with modeled noise 'noise_estimate_avg'
      // 'noiseU32 is in Q(qNoise) and 'noise_estimate' in Q(minNorm-stages)
      // To guarantee that we do not get wrap around when shifting to the same domain
      // we use the lowest one. Furthermore, we need to save 6 bits for the weighting.
      // 'noise_estimate_avg' can handle this operation by construction, but 'noiseU32'
      // may not.

      // Shift 'noiseU32' to 'q_domain_to_use'
      tmpU32no1 = WEBRTC_SPL_RSHIFT_U32(noiseU32[i], (int)qNoise - q_domain_to_use);
      // Shift 'noise_estimate_avg' to 'q_domain_to_use'
      tmpU32no2 = WEBRTC_SPL_RSHIFT_U32(noise_estimate_avg, inst->minNorm - inst->stages
                                        - q_domain_to_use);
      // Make a simple check to see if we have enough room for weighting 'tmpU32no1'
      // without wrap around
      nShifts = 0;
      if (tmpU32no1 & 0xfc000000) {
        tmpU32no1 = WEBRTC_SPL_RSHIFT_U32(tmpU32no1, 6);
        tmpU32no2 = WEBRTC_SPL_RSHIFT_U32(tmpU32no2, 6);
        nShifts = 6;
      }
      tmpU32no1 *= inst->blockIndex;
      tmpU32no2 *= (END_STARTUP_SHORT - inst->blockIndex);
      // Add them together and divide by startup length
      noiseU32[i] = WebRtcSpl_DivU32U16(tmpU32no1 + tmpU32no2, END_STARTUP_SHORT);
      // Shift back if necessary
      noiseU32[i] = WEBRTC_SPL_LSHIFT_U32(noiseU32[i], nShifts);
    }
    // Update new Q-domain for 'noiseU32'
    qNoise = q_domain_to_use;
  }
  // compute average signal during END_STARTUP_LONG time:
  // used to normalize spectral difference measure
  if (inst->blockIndex < END_STARTUP_LONG) {
    // substituting division with shift ending up in Q(-2*stages)
    inst->timeAvgMagnEnergyTmp
    += WEBRTC_SPL_RSHIFT_U32(inst->magnEnergy,
                             2 * inst->normData + inst->stages - 1);
    inst->timeAvgMagnEnergy = WebRtcSpl_DivU32U16(inst->timeAvgMagnEnergyTmp,
                                                  inst->blockIndex + 1);
  }

  //start processing at frames == converged+1
  // STEP 1: compute prior and post SNR based on quantile noise estimates

  // compute direct decision (DD) estimate of prior SNR: needed for new method
  satMax = (WebRtc_UWord32)1048575;// Largest possible value without getting overflow despite shifting 12 steps
  postShifts = 6 + qMagn - qNoise;
  nShifts = 5 - inst->prevQMagn + inst->prevQNoise;
  for (i = 0; i < inst->magnLen; i++) {
    // FLOAT:
    // post SNR
    // postLocSnr[i] = 0.0;
    // if (magn[i] > noise[i])
    // {
    //   postLocSnr[i] = magn[i] / (noise[i] + 0.0001);
    // }
    // // previous post SNR
    // // previous estimate: based on previous frame with gain filter (smooth is previous filter)
    //
    // prevNearSnr[i] = inst->prevMagnU16[i] / (inst->noisePrev[i] + 0.0001) * (inst->smooth[i]);
    //
    // // DD estimate is sum of two terms: current estimate and previous estimate
    // // directed decision update of priorSnr (or we actually store [2*priorSnr+1])
    //
    // priorLocSnr[i] = DD_PR_SNR * prevNearSnr[i] + (1.0 - DD_PR_SNR) * (postLocSnr[i] - 1.0);

    // calculate post SNR: output in Q11
    postLocSnr[i] = 2048; // 1.0 in Q11
    tmpU32no1 = WEBRTC_SPL_LSHIFT_U32((WebRtc_UWord32)magnU16[i], 6); // Q(6+qMagn)
    if (postShifts < 0) {
      tmpU32no2 = WEBRTC_SPL_RSHIFT_U32(noiseU32[i], -postShifts); // Q(6+qMagn)
    } else {
      tmpU32no2 = WEBRTC_SPL_LSHIFT_U32(noiseU32[i], postShifts); // Q(6+qMagn)
    }
    if (tmpU32no1 > tmpU32no2) {
      // Current magnitude larger than noise
      tmpU32no1 = WEBRTC_SPL_LSHIFT_U32(tmpU32no1, 11); // Q(17+qMagn)
      if (tmpU32no2 > 0) {
        tmpU32no1 = WEBRTC_SPL_UDIV(tmpU32no1, tmpU32no2); // Q11
        postLocSnr[i] = WEBRTC_SPL_MIN(satMax, tmpU32no1); // Q11
      } else {
        postLocSnr[i] = satMax;
      }
    }

    // calculate prevNearSnr[i] and save for later instead of recalculating it later
    nearMagnEst = WEBRTC_SPL_UMUL_16_16(inst->prevMagnU16[i], inst->noiseSupFilter[i]); // Q(prevQMagn+14)
    tmpU32no1 = WEBRTC_SPL_LSHIFT_U32(nearMagnEst, 3); // Q(prevQMagn+17)
    tmpU32no2 = WEBRTC_SPL_RSHIFT_U32(inst->prevNoiseU32[i], nShifts); // Q(prevQMagn+6)

    if (tmpU32no2 > 0) {
      tmpU32no1 = WEBRTC_SPL_UDIV(tmpU32no1, tmpU32no2); // Q11
      tmpU32no1 = WEBRTC_SPL_MIN(satMax, tmpU32no1); // Q11
    } else {
      tmpU32no1 = satMax; // Q11
    }
    prevNearSnr[i] = tmpU32no1; // Q11

    //directed decision update of priorSnr
    tmpU32no1 = WEBRTC_SPL_UMUL_32_16(prevNearSnr[i], DD_PR_SNR_Q11); // Q22
    tmpU32no2 = WEBRTC_SPL_UMUL_32_16(postLocSnr[i] - 2048, ONE_MINUS_DD_PR_SNR_Q11); // Q22
    priorSnr = tmpU32no1 + tmpU32no2 + 512; // Q22 (added 512 for rounding)
    // priorLocSnr = 1 + 2*priorSnr
    priorLocSnr[i] = 2048 + WEBRTC_SPL_RSHIFT_U32(priorSnr, 10); // Q11
  } // end of loop over frequencies
  // done with step 1: DD computation of prior and post SNR

  // STEP 2: compute speech/noise likelihood

  //compute difference of input spectrum with learned/estimated noise spectrum
  WebRtcNsx_ComputeSpectralDifference(inst, magnU16);
  //compute histograms for determination of parameters (thresholds and weights for features)
  //parameters are extracted once every window time (=inst->modelUpdate)
  //counter update
  inst->cntThresUpdate++;
  flag = (int)(inst->cntThresUpdate == inst->modelUpdate);
  //update histogram
  WebRtcNsx_FeatureParameterExtraction(inst, flag);
  //compute model parameters
  if (flag) {
    inst->cntThresUpdate = 0; // Reset counter
    //update every window:
    // get normalization for spectral difference for next window estimate

    // Shift to Q(-2*stages)
    inst->curAvgMagnEnergy = WEBRTC_SPL_RSHIFT_U32(inst->curAvgMagnEnergy, STAT_UPDATES);

    tmpU32no1 = (inst->curAvgMagnEnergy + inst->timeAvgMagnEnergy + 1) >> 1; //Q(-2*stages)
    // Update featureSpecDiff
    if ((tmpU32no1 != inst->timeAvgMagnEnergy) && (inst->featureSpecDiff) &&
        (inst->timeAvgMagnEnergy > 0)) {
      norm32no1 = 0;
      tmpU32no3 = tmpU32no1;
      while (0xFFFF0000 & tmpU32no3) {
        tmpU32no3 >>= 1;
        norm32no1++;
      }
      tmpU32no2 = inst->featureSpecDiff;
      while (0xFFFF0000 & tmpU32no2) {
        tmpU32no2 >>= 1;
        norm32no1++;
      }
      tmpU32no3 = WEBRTC_SPL_UMUL(tmpU32no3, tmpU32no2);
      tmpU32no3 = WEBRTC_SPL_UDIV(tmpU32no3, inst->timeAvgMagnEnergy);
      if (WebRtcSpl_NormU32(tmpU32no3) < norm32no1) {
        inst->featureSpecDiff = 0x007FFFFF;
      } else {
        inst->featureSpecDiff = WEBRTC_SPL_MIN(0x007FFFFF,
            WEBRTC_SPL_LSHIFT_U32(tmpU32no3, norm32no1));
      }
    }

    inst->timeAvgMagnEnergy = tmpU32no1; // Q(-2*stages)
    inst->curAvgMagnEnergy = 0;
  }

  //compute speech/noise probability
  WebRtcNsx_SpeechNoiseProb(inst, nonSpeechProbFinal, priorLocSnr, postLocSnr);

  //time-avg parameter for noise update
  gammaNoise = NOISE_UPDATE_Q8; // Q8

  maxNoiseU32 = 0;
  postShifts = inst->prevQNoise - qMagn;
  nShifts = inst->prevQMagn - qMagn;
  for (i = 0; i < inst->magnLen; i++) {
    // temporary noise update: use it for speech frames if update value is less than previous
    // the formula has been rewritten into:
    // noiseUpdate = noisePrev[i] + (1 - gammaNoise) * nonSpeechProb * (magn[i] - noisePrev[i])

    if (postShifts < 0) {
      tmpU32no2 = WEBRTC_SPL_RSHIFT_U32(magnU16[i], -postShifts); // Q(prevQNoise)
    } else {
      tmpU32no2 = WEBRTC_SPL_LSHIFT_U32(magnU16[i], postShifts); // Q(prevQNoise)
    }
    if (prevNoiseU16[i] > tmpU32no2) {
      sign = -1;
      tmpU32no1 = prevNoiseU16[i] - tmpU32no2;
    } else {
      sign = 1;
      tmpU32no1 = tmpU32no2 - prevNoiseU16[i];
    }
    noiseUpdateU32 = inst->prevNoiseU32[i]; // Q(prevQNoise+11)
    tmpU32no3 = 0;
    if ((tmpU32no1) && (nonSpeechProbFinal[i])) {
      // This value will be used later, if gammaNoise changes
      tmpU32no3 = WEBRTC_SPL_UMUL_32_16(tmpU32no1, nonSpeechProbFinal[i]); // Q(prevQNoise+8)
      if (0x7c000000 & tmpU32no3) {
        // Shifting required before multiplication
        tmpU32no2
          = WEBRTC_SPL_UMUL_32_16(WEBRTC_SPL_RSHIFT_U32(tmpU32no3, 5), gammaNoise); // Q(prevQNoise+11)
      } else {
        // We can do shifting after multiplication
        tmpU32no2
          = WEBRTC_SPL_RSHIFT_U32(WEBRTC_SPL_UMUL_32_16(tmpU32no3, gammaNoise), 5); // Q(prevQNoise+11)
      }
      if (sign > 0) {
        noiseUpdateU32 += tmpU32no2; // Q(prevQNoise+11)
      } else {
        // This operation is safe. We can never get wrap around, since worst
        // case scenario means magnU16 = 0
        noiseUpdateU32 -= tmpU32no2; // Q(prevQNoise+11)
      }
    }

    //increase gamma (i.e., less noise update) for frame likely to be speech
    prevGammaNoise = gammaNoise;
    gammaNoise = NOISE_UPDATE_Q8;
    //time-constant based on speech/noise state
    //increase gamma (i.e., less noise update) for frames likely to be speech
    if (nonSpeechProbFinal[i] < ONE_MINUS_PROB_RANGE_Q8) {
      gammaNoise = GAMMA_NOISE_TRANS_AND_SPEECH_Q8;
    }

    if (prevGammaNoise != gammaNoise) {
      // new noise update
      // this line is the same as above, only that the result is stored in a different variable and the gammaNoise
      // has changed
      //
      // noiseUpdate = noisePrev[i] + (1 - gammaNoise) * nonSpeechProb * (magn[i] - noisePrev[i])

      if (0x7c000000 & tmpU32no3) {
        // Shifting required before multiplication
        tmpU32no2
          = WEBRTC_SPL_UMUL_32_16(WEBRTC_SPL_RSHIFT_U32(tmpU32no3, 5), gammaNoise); // Q(prevQNoise+11)
      } else {
        // We can do shifting after multiplication
        tmpU32no2
          = WEBRTC_SPL_RSHIFT_U32(WEBRTC_SPL_UMUL_32_16(tmpU32no3, gammaNoise), 5); // Q(prevQNoise+11)
      }
      if (sign > 0) {
        tmpU32no1 = inst->prevNoiseU32[i] + tmpU32no2; // Q(prevQNoise+11)
      } else {
        tmpU32no1 = inst->prevNoiseU32[i] - tmpU32no2; // Q(prevQNoise+11)
      }
      if (noiseUpdateU32 > tmpU32no1) {
        noiseUpdateU32 = tmpU32no1; // Q(prevQNoise+11)
      }
    }
    noiseU32[i] = noiseUpdateU32; // Q(prevQNoise+11)
    if (noiseUpdateU32 > maxNoiseU32) {
      maxNoiseU32 = noiseUpdateU32;
    }

    // conservative noise update
    // // original FLOAT code
    // if (prob_speech < PROB_RANGE) {
    // inst->avgMagnPause[i] = inst->avgMagnPause[i] + (1.0 - gamma_pause)*(magn[i] - inst->avgMagnPause[i]);
    // }

    tmp32no2 = WEBRTC_SPL_SHIFT_W32(inst->avgMagnPause[i], -nShifts);
    if (nonSpeechProbFinal[i] > ONE_MINUS_PROB_RANGE_Q8) {
      if (nShifts < 0) {
        tmp32no1 = (WebRtc_Word32)magnU16[i] - tmp32no2; // Q(qMagn)
        tmp32no1 = WEBRTC_SPL_MUL_32_16(tmp32no1, ONE_MINUS_GAMMA_PAUSE_Q8); // Q(8+prevQMagn+nShifts)
        tmp32no1 = WEBRTC_SPL_RSHIFT_W32(tmp32no1 + 128, 8); // Q(qMagn)
      } else {
        tmp32no1 = WEBRTC_SPL_LSHIFT_W32((WebRtc_Word32)magnU16[i], nShifts)
                   - inst->avgMagnPause[i]; // Q(qMagn+nShifts)
        tmp32no1 = WEBRTC_SPL_MUL_32_16(tmp32no1, ONE_MINUS_GAMMA_PAUSE_Q8); // Q(8+prevQMagn+nShifts)
        tmp32no1 = WEBRTC_SPL_RSHIFT_W32(tmp32no1 + (128 << nShifts), 8 + nShifts); // Q(qMagn)
      }
      tmp32no2 += tmp32no1; // Q(qMagn)
    }
    inst->avgMagnPause[i] = tmp32no2;
  } // end of frequency loop

  norm32no1 = WebRtcSpl_NormU32(maxNoiseU32);
  qNoise = inst->prevQNoise + norm32no1 - 5;
  // done with step 2: noise update

  // STEP 3: compute dd update of prior snr and post snr based on new noise estimate
  nShifts = inst->prevQNoise + 11 - qMagn;
  for (i = 0; i < inst->magnLen; i++) {
    // FLOAT code
    // // post and prior SNR
    // curNearSnr = 0.0;
    // if (magn[i] > noise[i])
    // {
    // curNearSnr = magn[i] / (noise[i] + 0.0001) - 1.0;
    // }
    // // DD estimate is sum of two terms: current estimate and previous estimate
    // // directed decision update of snrPrior
    // snrPrior = DD_PR_SNR * prevNearSnr[i] + (1.0 - DD_PR_SNR) * curNearSnr;
    // // gain filter
    // tmpFloat1 = inst->overdrive + snrPrior;
    // tmpFloat2 = snrPrior / tmpFloat1;
    // theFilter[i] = tmpFloat2;

    // calculate curNearSnr again, this is necessary because a new noise estimate has been made since then. for the original
    curNearSnr = 0; // Q11
    if (nShifts < 0) {
      // This case is equivalent with magn < noise which implies curNearSnr = 0;
      tmpMagnU32 = (WebRtc_UWord32)magnU16[i]; // Q(qMagn)
      tmpNoiseU32 = WEBRTC_SPL_LSHIFT_U32(noiseU32[i], -nShifts); // Q(qMagn)
    } else if (nShifts > 17) {
      tmpMagnU32 = WEBRTC_SPL_LSHIFT_U32(magnU16[i], 17); // Q(qMagn+17)
      tmpNoiseU32 = WEBRTC_SPL_RSHIFT_U32(noiseU32[i], nShifts - 17); // Q(qMagn+17)
    } else {
      tmpMagnU32 = WEBRTC_SPL_LSHIFT_U32((WebRtc_UWord32)magnU16[i], nShifts); // Q(qNoise_prev+11)
      tmpNoiseU32 = noiseU32[i]; // Q(qNoise_prev+11)
    }
    if (tmpMagnU32 > tmpNoiseU32) {
      tmpU32no1 = tmpMagnU32 - tmpNoiseU32; // Q(qCur)
      norm32no2 = WEBRTC_SPL_MIN(11, WebRtcSpl_NormU32(tmpU32no1));
      tmpU32no1 = WEBRTC_SPL_LSHIFT_U32(tmpU32no1, norm32no2); // Q(qCur+norm32no2)
      tmpU32no2 = WEBRTC_SPL_RSHIFT_U32(tmpNoiseU32, 11 - norm32no2); // Q(qCur+norm32no2-11)
      if (tmpU32no2 > 0) {
        tmpU32no1 = WEBRTC_SPL_UDIV(tmpU32no1, tmpU32no2); // Q11
      }
      curNearSnr = WEBRTC_SPL_MIN(satMax, tmpU32no1); // Q11
    }

    //directed decision update of priorSnr
    // FLOAT
    // priorSnr = DD_PR_SNR * prevNearSnr + (1.0-DD_PR_SNR) * curNearSnr;

    tmpU32no1 = WEBRTC_SPL_UMUL_32_16(prevNearSnr[i], DD_PR_SNR_Q11); // Q22
    tmpU32no2 = WEBRTC_SPL_UMUL_32_16(curNearSnr, ONE_MINUS_DD_PR_SNR_Q11); // Q22
    priorSnr = tmpU32no1 + tmpU32no2; // Q22

    //gain filter
    tmpU32no1 = (WebRtc_UWord32)(inst->overdrive)
                + WEBRTC_SPL_RSHIFT_U32(priorSnr + 8192, 14); // Q8
    assert(inst->overdrive > 0);
    tmpU16no1 = (WebRtc_UWord16)WEBRTC_SPL_UDIV(priorSnr + (tmpU32no1 >> 1), tmpU32no1); // Q14
    inst->noiseSupFilter[i] = WEBRTC_SPL_SAT(16384, tmpU16no1, inst->denoiseBound); // 16384 = Q14(1.0) // Q14

    // Weight in the parametric Wiener filter during startup
    if (inst->blockIndex < END_STARTUP_SHORT) {
      // Weight the two suppression filters
      tmpU32no1 = WEBRTC_SPL_UMUL_16_16(inst->noiseSupFilter[i],
                                        (WebRtc_UWord16)inst->blockIndex);
      tmpU32no2 = WEBRTC_SPL_UMUL_16_16(noiseSupFilterTmp[i],
                                        (WebRtc_UWord16)(END_STARTUP_SHORT
                                                         - inst->blockIndex));
      tmpU32no1 += tmpU32no2;
      inst->noiseSupFilter[i] = (WebRtc_UWord16)WebRtcSpl_DivU32U16(tmpU32no1,
                                                                    END_STARTUP_SHORT);
    }
  } // end of loop over frequencies
  //done with step3

  // save noise and magnitude spectrum for next frame
  inst->prevQNoise = qNoise;
  inst->prevQMagn = qMagn;
  if (norm32no1 > 5) {
    for (i = 0; i < inst->magnLen; i++) {
      inst->prevNoiseU32[i] = WEBRTC_SPL_LSHIFT_U32(noiseU32[i], norm32no1 - 5); // Q(qNoise+11)
      inst->prevMagnU16[i] = magnU16[i]; // Q(qMagn)
    }
  } else {
    for (i = 0; i < inst->magnLen; i++) {
      inst->prevNoiseU32[i] = WEBRTC_SPL_RSHIFT_U32(noiseU32[i], 5 - norm32no1); // Q(qNoise+11)
      inst->prevMagnU16[i] = magnU16[i]; // Q(qMagn)
    }
  }

  WebRtcNsx_DataSynthesis(inst, outFrame);
#ifdef NS_FILEDEBUG
  fwrite(outframe, sizeof(short), inst->blockLen10ms, inst->outfile);
#endif

  //for H band:
  // only update data buffer, then apply time-domain gain is applied derived from L band
  if (inst->fs == 32000) {
    // update analysis buffer for H band
    // append new data to buffer FX
    WEBRTC_SPL_MEMCPY_W16(inst->dataBufHBFX, inst->dataBufHBFX + inst->blockLen10ms, inst->anaLen - inst->blockLen10ms);
    WEBRTC_SPL_MEMCPY_W16(inst->dataBufHBFX + inst->anaLen - inst->blockLen10ms, speechFrameHB, inst->blockLen10ms);
    // range for averaging low band quantities for H band gain

    gainTimeDomainHB = 16384; // 16384 = Q14(1.0)
    //average speech prob from low band
    //average filter gain from low band
    //avg over second half (i.e., 4->8kHz) of freq. spectrum
    tmpU32no1 = 0; // Q12
    tmpU16no1 = 0; // Q8
    for (i = inst->anaLen2 - (inst->anaLen2 >> 2); i < inst->anaLen2; i++) {
      tmpU16no1 += nonSpeechProbFinal[i]; // Q8
      tmpU32no1 += (WebRtc_UWord32)(inst->noiseSupFilter[i]); // Q14
    }
    avgProbSpeechHB = (WebRtc_Word16)(4096
        - WEBRTC_SPL_RSHIFT_U16(tmpU16no1, inst->stages - 7)); // Q12
    avgFilterGainHB = (WebRtc_Word16)WEBRTC_SPL_RSHIFT_U32(
        tmpU32no1, inst->stages - 3); // Q14

    // // original FLOAT code
    // // gain based on speech probability:
    // avg_prob_speech_tt=(float)2.0*avg_prob_speech-(float)1.0;
    // gain_mod=(float)0.5*((float)1.0+(float)tanh(avg_prob_speech_tt)); // between 0 and 1

    // gain based on speech probability:
    // original expression: "0.5 * (1 + tanh(2x-1))"
    // avgProbSpeechHB has been anyway saturated to a value between 0 and 1 so the other cases don't have to be dealt with
    // avgProbSpeechHB and gainModHB are in Q12, 3607 = Q12(0.880615234375) which is a zero point of
    // |0.5 * (1 + tanh(2x-1)) - x| - |0.5 * (1 + tanh(2x-1)) - 0.880615234375| meaning that from that point the error of approximating
    // the expression with f(x) = x would be greater than the error of approximating the expression with f(x) = 0.880615234375
    // error: "|0.5 * (1 + tanh(2x-1)) - x| from x=0 to 0.880615234375" -> http://www.wolframalpha.com/input/?i=|0.5+*+(1+%2B+tanh(2x-1))+-+x|+from+x%3D0+to+0.880615234375
    // and:  "|0.5 * (1 + tanh(2x-1)) - 0.880615234375| from x=0.880615234375 to 1" -> http://www.wolframalpha.com/input/?i=+|0.5+*+(1+%2B+tanh(2x-1))+-+0.880615234375|+from+x%3D0.880615234375+to+1
    gainModHB = WEBRTC_SPL_MIN(avgProbSpeechHB, 3607);

    // // original FLOAT code
    // //combine gain with low band gain
    // if (avg_prob_speech < (float)0.5) {
    // gain_time_domain_HB=(float)0.5*gain_mod+(float)0.5*avg_filter_gain;
    // }
    // else {
    // gain_time_domain_HB=(float)0.25*gain_mod+(float)0.75*avg_filter_gain;
    // }


    //combine gain with low band gain
    if (avgProbSpeechHB < 2048) {
      // 2048 = Q12(0.5)
      // the next two lines in float are  "gain_time_domain = 0.5 * gain_mod + 0.5 * avg_filter_gain"; Q2(0.5) = 2 equals one left shift
      gainTimeDomainHB = (gainModHB << 1) + (avgFilterGainHB >> 1); // Q14
    } else {
      // "gain_time_domain = 0.25 * gain_mod + 0.75 * agv_filter_gain;"
      gainTimeDomainHB = (WebRtc_Word16)WEBRTC_SPL_MUL_16_16_RSFT(3, avgFilterGainHB, 2); // 3 = Q2(0.75); Q14
      gainTimeDomainHB += gainModHB; // Q14
    }
    //make sure gain is within flooring range
    gainTimeDomainHB
      = WEBRTC_SPL_SAT(16384, gainTimeDomainHB, (WebRtc_Word16)(inst->denoiseBound)); // 16384 = Q14(1.0)


    //apply gain
    for (i = 0; i < inst->blockLen10ms; i++) {
      outFrameHB[i]
        = (WebRtc_Word16)WEBRTC_SPL_MUL_16_16_RSFT(gainTimeDomainHB, inst->dataBufHBFX[i], 14); // Q0
    }
  } // end of H band gain computation

  return 0;
}


